I don't know what part of the world are you from, but here in Poland, ordinary 400W Bi-Facial panel costs around $80/pc, when buying from wholesaler which are plenty and accessible even to non-companies (as a proof, I did buy 4pcs myself). And if you buy in bulk, it can even be $50/pc.

But boy how much the mounting system costs - it's at least 3 times the cost of the panes if you buy them in 2xN or 4xN bulk and I'm excluding labor here.