Nvidia 1050ti is probably the best dollars/hash rate right now.  That doesn't take into account efficiency...it will be a little $ per MH to operate.  GPU are overpriced right now and I think as manufactures catch up to demand I expect prices to drop quite a bit by mid summer.  That's what I'm hoping at least Anyway, here's an article with some info about the card.  They are pretty available.

http://1stminingrig.com/nvidia-geforce-gtx-1050-1050ti-mining-performance-review/

Also blockoperations.com is a resource I found very helpful.  There are some good guides on there and lots of general mining info.

Hope that helps.