100 subscriber contest on youtube

I've got a youtube channel and I've almost reached 100 lovely subbies!! I still can't believe I made it past 10! It's crazy! But I'm so grateful I really want to give somthing back. I'm going to be holding a little contest on my channel. You must be a subscriber to enter, but that's about it. As I'm still fairly new at this I don't have the luxury of being sponsored or sent free things, so any prize I give will be purchased with my own cash 9which I don't have a lot of) So I really want to make sure I get somthing people are going to want and use and isn't going to get lost and forgotten in the bottom of a drawer somewhere!
If anyone has any ideas/suggestions for a prize please let me know. I want it to be makeup/beauty related and as I said I don't have a lot of money but that's my only stipulation.
Comments below please!!!