Good sites for buying keys

Good day all, hope you guys are doing well.

I've recently become quite a bit more active on SG, joining groups and participating in events. This in turn has led to an increase in wins. I don't like to receive without giving back, which brings me to my question.

I am in fact still a student and as it is with most students, not super well-off. I don't really want to get dirt cheap keys of bad games. As you can see from my profile, I have been trying to gift somewhat well-known indie titles that aren't complete flops. So where do you guys all get your keys from? I would like to contribute more overall (within my means of course) and do want to try give decent keys.

Some good key buying site suggestions would be greatly appreciated. Thanks :)