WHAT'S A CHEAP CHRISMAS PRESENT I CAN BUY A 17 YEAROLD SISTER (im kinda broke right now)

I would make something for her. Something she would like.

Costa или Starbucks gift card?

Buy:
A coffee mug with a cute ribbon and note on the ear talking about how much Ты Любовь her

A scarf, mitten, and hat set/ или fuzzy Рождество socks for a cheaper option

Throw some cadbury deluxe Шоколад in there

This should be about $15. It is a meaningful and wintery, yet inexpensive.

Well I am like basically 17 years old and I would not mind getting a big bag of marshmallows and a box of вишня jello .

Supras.

I'm obsessed with звезда signs and stuff like that, so my Друзья and I often get each other little cute trinkets that have something to do with each of our звезда signs, so each present is special to them ^^
I Любовь getting scorpio gifts and stuff like that x)

Get something that relates to HER. Small things, her звезда sign, her birthstone colour, little details make it special :) Can get those things in any gift shop.

Draw her something she likes, write a poem for her...
Nothing is cheaper than free! Though, it does take time...

Socks

It all depends on what your sister likes.

Perhaps get her a little basket and add Болталка little things to it that Ты know she likes.

Be it chocolate, soaps, perfumes, flowers, CDs, earrings, bracelets, jewelry, drinks, cheeses, chips, или maybe all plus more...

but considering that your budget is small, Ты could choose a few of these или something similar.

A gift basket and a card would be cool. :) или just a card with money in it. Everyone loves those. XD