Why are you being like this???
I don't blame you dude, I get you to a point. I understand your situation. But come on, think about this. You don't have enough money AT ALL. And even so, would you pay a 50 bucks dinner to a girl you barely know? Why? Because you feel like it, or because you don't think you're cool enough, and she wouldn't want to hang out with you in another situation? If the second, get some self esteem. And remember it's no rush since there are more girls out there. If you just feel like it, anyway remember you don't even have much money, I would advise a normal date and you save the money.
Maybe you're trying to "look cool" by finding a neat way out of this, but inside you're worrying like hell and all. I doubt it will work, because you have some other problems and no way you can pull off a "DJ" image while inside you're still worryed\insecure. That is incongruent, and she will probably know something's wrong with you. Even if you find the perfect ****y and funny line to get out of this smoothly, you worryed a good while about this and that isn't attractive. (If you did worry a lot, I dunno if you really did).
Don't you think she will understand if you tell her that you have to go somewhere else because you don't have much money? She has to understand it... If she doesn't her problem. I think it's fair to say that.
Anyways, a "real dj" is fun as heck anyways, he is entertaining (you don't have to be like that, i'm just saying. I think all people with high self esteem are super fun to be around. But they don't need to try to be fun to gain approval from girls.) and confident and girls like to hang out with him anyway, money or not... I think that was your problem, you didn't want to look like you didn't have much money, was that it? If so, I think your self esteem is low. Because you don't feel like you can take her to a restaurant without paying much, because you don't think she will "like you" unless you have lots of money to spend...
Btw "hiding the cupon" do you really need to do that? I think you're worrying too much. I think you may have to think about your self esteem and confidence...
But I suppose it could be a lot worse tho... I guess these things are normal, at least you have the SS boards to help you out!
Good luck!