Buying knife

https://www.steamgifts.com/trades

If you intend to buy games to pay the knife owner, then why not just buy the knife yourself? :P

Well I could but I'm trying to get a knife for a bit less then full price

I doubt you will find someone, because if you buy a gift you need to wait 30 days for it to be tradable.
Well, you could always gift it, but after you get the knife you can always revoke the gift and scam the dude who gives you a knife.
You don't have much rep to demonstrate I may be wrong, so you will better buy a knife directly