You will never get the shipping prices they get. Good luck sending a panel back via usps or UPS for under $50 for something that big + their cost to ship back. Out of country easily double it the costs. Same cost as a new cheaper panel minus all the down time. Warranties mean nothing. Walmart can't even het their money back from roof fires with the solar city panels that were used.The higher prices seem to be brand new with factory warranty.
At least with a trusted liquidator like SanTan, you can get panels that are a few years old and he gives you a 1-year warranty. Assuming you can hook them up and detect failures (I need to get myself a clamp-on DC ammeter), you can confirm they're good.
One poster has mentioned leakage issues with Trina. I haven't seen other references.
Some forum members are buying as cheap as possible, $0.12 to $0.20/watt.
I went for a premium brand name and paid a higher price. It isn't big bucks unless you buy a relatively huge quantity.
When payback vs. utility rates is down around 2 years, it is hard to lose. Especially with 1-year warranty! The only question is how far ahead you come out before having to replace the panels, assuming that ever happens.