Because of the mining boom video cards have massively increased in price over the last couple of months that basically all of the budget PC Builders cant afford upgrades on Video cards.
Here is one that i find really good but of course not the lowest:
https://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=rx+580&ignorear=0&N=-1&isNodeId=1