Erwin wrote:
Giving gifts to your gf is weird. As if she'd be a prostitute or something.
Gift giving is often seen socially as a sign of affection, not as a non-monetary exchange of goods. Not all relationships are based on economics.
The OP was stressing that this gift was for a female friend and not a girlfriend so that he didn't get gift suggestions that were too intimate for the relationship nor too expensive.
OP, I think this is a very sweet gesture. If purple is her favorite color, a purple fashion accessory that fall within your price range would be very well-received I think. Examples to look for would be earrings, a bracelet, a necklace, a scarf, or headband. If you feel that taste is too subjective, purple colored stationery is also a good gift that fits within your budget.
Hope this helps.