GPU prices are totally insane right now.

A week ago you could get some decent prices for mid level cards like the RX 570 4gb or 1060 6gb. Now those cards have gone through the roof. Miners like myself are buying up cards like crazy in anticipation of increasing Crypto prices this year.
AMD and Nvidia cannot keep up. Nor do they want to. They don't want the market to be flooded with used cards if crypto falls dramatically. They are selling out everything they produce.
Last week the price for an MSI RX 570 4gb card was around $249-$270 at Newegg and Microcenter. You cannot find them at retailers and if you do any 570 is $500 plus. The prices on Ebay are now less than the retailers for these cards. Even with the 10% taken by Ebay and free shipping.
In my opinion, over the next month it will only get worse. You can't find Vegas and if you want a Vega you can get one 3rd party for $1500. Microcenter is now selling 1080 Ti's for $1500 , as well.
There may be some relief if AMD and Nvidia launch the rumored mining cards, but don't be surprised if they sell out instantly. People are insane for mining right now. They see huge growth and so do I. The market is ripe for a new player to manufacture GPUs but as I understand it Nvidia and AMD hold all the patents. Could a new company emerge? Only time will tell. Maybe Asics will be developed for some of these currencies, but until then the GPU drought of 2018 will continue.

Good luck out there if you find any deals, take advantage of them. My guess is summer time before we see some relief.