I have a concern about my sexual experiences. You see, I am a 24 year old girl and am a virgin. Although I have had many opportunities whereby I could have had sex, I did not, since it is very important to me to have sex after marriage and share physical intimacy with my husband. As a result, I usually prefer to date someone who is 27 or above (since older guys are more established and looking to settle down).

Very wise and very true! 

So far in life, I have been in two long-term relationships: One in which my boyfriend eventually demanded sex (and since I did not comply, we broke up because of me- I did not think it was fair to him to wait for me.

Really it wasn't because of you, because the real thing that caused it was him demanding sex.  The fact that you chose to end it was irrelevant to the cause, it was caused by his demand for sex.
 

In the second relationship, he was understanding about this but things did not work out when he went abroad to study and neither of us believe in long-distance relationships so it ended.

Long distance relationships can sometimes work, but very rarely.  When you are both such a distance away, you stop knowing each other very well and become virtual strangers.  Each of you are meeting other people who you will probably know more than your partner and each of you will equally get attached to people you are in contact with in person everyday, so in general long distance relationships rarely work out.
 

My questions from you are: how do I tell this to a man who I start dating and also, will he think less of me for being inexperienced?

The fact that you are inexperienced means nothing to him.  Lots of men would love to take the virginity of a woman.  They maybe a bit scared of bleeding or a bit scared that the woman is resistant to having sex with him or maybe he may cause her pain during sex and result in her not being interested in him anymore.  But really guys are generally seen as the ones that should have experience.
 

I am afraid that he may find someone else who can give him sex before marriage and so I am terrified of being hurt.

I agree that has to be a big concern nowadays.  Blokes want sex, it's a need that we have and most of us are not so keen to keep our virginity.  Once we've had sex once it becomes a drug, that we need to get a regular fix on sex.  A lot of women will provide a guy with casual sex nowadays and indeed I think many women don't just feel pushed into casual sex but actually enjoy it (though correct me if I'm wrong).  There are other women that feel as though they have to have sex to hold onto their man, but this basically just creates a situation where an unsuitable guy will stay with you for longer than he anticipated because you are giving him sex. 

For these reasons there will be an endless amount of temptations for a guy.  Are you worth waiting for?  Are you worth him being celebate until he gets married?  Will he manage to resist temptation when he has women tempting him? Will his hormones get in the way of stopping him from having sex with other women?

I personally believe that if one is enthusiastic with one's partner during sex and truly loves them, the lack (or no) experience makes up for it (I don't expect earth-shattering sex on my first time though).

The fact that you are inexperienced and are a virgin is really not an issue to men.  The fact that you won't allow sex before marriage is.  I always recommend to women not to have sex with men for at least the first month or so of a relationship.   This weeds out the men that just want to use a woman for sex from the guys that actually might want a long term relationship. 

I personally truly respect the fact that you don't like sex before marriage and in a way I wish all women adopted this attitude because they don't realise the damage they are doing to their future.  But the fact is we live in a culture where sex is freely available nowadays, so men are less accepting of a woman that doesn't believe in sex before marriage.  There are men out their that will respect no sex before marriage but they are now in an a minority, I have even heard that there are dating web sites devoted to people with this belief.

Really though my personal view is that if a guy really does love you, you have the right personality for him and you are good looking, then I believe a man should respect your right and will be willing to wait.  I have some doubt about whether the majority of men would be able to stick that out nowadays though, because of the culture.

I do masturbate quite often and know exactly what turns me on.

Men should be able to turn you on, and should eventually work out how to turn you.  Whether the man is a virgin or not, he should be able to explore sex with you in a mutually loving marriage and satisfy you and equally satisfy himself. 

Do men value virgins or will this quality of mine turn men off?

If you asked me what kind of women we find attractive, for long term relationships, I would have to say young, fertile women, that have had sex with as few men as possible and preferably a virgin.  If you asked me who men want to have sex with for just sexual flings, I would say easy women, that have sex regularly and who are willing to push the boundaries in what they want to do with sex.

Ultimately a guy that wants to get married, wants a healthy young woman who has not had sex with many partners, though he maybe doesn't conciously think this, his brain biologically pushes him towards this type of woman.  The more blokes a woman has had sex with the less fertile she might be.  This could be due to cervical cancer, endometriosis caused by sexually transmitted diseases or abortions and previous pregnancies with other partners, all of which can affect her fertility with a new partner.  Plus a guy doesn't want to catch any bad diseases and he is unlikely to catch anything from a virgin, apart from maybe thrush which is just as common in virgins as it is in sexually active women.

So to answer your question, the fact that you are a virgin will not turn men off.  The fact that you don't believe in sex before marriage will probably turn most men off nowadays.  But really if you want to find a man that really does love you, then you should at least make him wait a few months to have sex and ideally if you can find a bloke that will last until marriage then that is the ultimate holy grail nowadays.  You certainly have to look for a certain type of bloke, particularly a guy that you may think is himself inexperienced and who could potentially be patient.  If he's 24 and hasn't managed to have sex yet, then surely he should be at least be able to last another year or two until you get married.  But guys that consistently have sex with loads of women, I doubt they would last with you, without at least having a bit on the side from elsewhere.  If you want to get this type of guy nowadays, then ultimately you would have to be absolutely gorgeous and have a good rapport with him too.

I would certainly make this sacrifice of no sex before marriage, if you were the right woman for me, so I don't see why other men shouldn't!