Check eBay. You can sort by distance if you want to pick them up. That's how I discovered SanTan.
Also Craigslist.
Call SanTan; they may have something that fits your needs but too few to bother posting on website.
Due to recent world situation, many people suddenly became interested in alternative energy, drying up a lot of supply.
Installers doing large projects buy extras, then dump what's left over to liquidators like SanTan. You could try to find local ones, see if you can buy a random lot from them.
But if you can wait until things blow over, market might settle down again.
I'd expect 3kW of panels to cost anywhere between $400 and $3000, depending on used/new and trashed bad brands vs. quality brands.
Find many great new & used options and get the best deals for PALLET USED JINKOSOLAR 305 WATT PHOTOVOLTAIC SOLAR PANELS... (12) at the best online prices at eBay! Free shipping for many products!
www.ebay.com
The panels were made back in 2014 and were in use for 6 years, coming off a solar farm. We have bought them for all markets including Grid Tie, Overseas and DIY markets which they will thrive in. The panels as well still have their UL sticker on them which makes them eligible for Grid Tie...
www.ebay.com