long story short, theres a chick in my college that likes me but it never went down to well, but shes kind of cares to much about her reputation in the school and doesnt like to look like a dick and stuff, because of previous experiences with lads.

Anyway, i can tell she still likes me but, because shes a HB9, would having sex with a HB6/7 (6 face, 8 figure) lower my value? I was planning to get her jealous by showing that i dont care about her and then she'll chase me but im unsure whether it will work. Whats you opinion of this?

Dude WTF is wrong with you, she likes you and you would like to punish her for that, why? It's simple, she likes you, you like her, what is the problem?
Make some sexual statement, tell her what you feel about her it's a lot more simple than: ''OK I gonna game this other girl for as long as I have to, have sex with her and the tell that to my friends, who'll tell HB9 and that'll make her jelaous.''
Don't complicate it, you've already got logistics in your pocket, you just need to finish the details

_________________
How my life looks like right now: STUDY HARD, PARTY HARD

Have you actually tried isolating her and trying it on? you might wanna do that before you complicate it to the Nth degree.

And never think of anything in the negative, you should always think of the positive effects or ways you can exploit it to be a positive thing.

If you bang an average looking girl, you can use them as an example of saying I dont really care about looks im more interested in the person and the emotional experience we shared, girls eat that shit up, even if your target isnt present sure as shit, it will be discussed and spread around thats 'your view' and they will hear about it (within a social circle) which WILL influence them if you approach them.

Thats the only way I can see that helping, jealousy angle is just ... meh, and then you have emotional damage to deal with from the 3rd used party. So make sure they understand your just sharing a casual experience together and you dont want anything serious otherwise dont, because you will come off as a dick, although tbfh you will be coming off as what she is trying to avoid/worried about getting attached to again. Personally I wouldnt do it, work on her, and isolate and escalate, if she doesnt want to why are you wasting your time.

p.s Being the discrete lover is superior to bragging about banging girls or compromising her status, if you quietly sleep with girls and then shut the fuck up you will get alot more action, THEY do talk, and it helps those in relationships to be more open to advances since they know you wont compromise them.