I ended up buying 12 fixtures. I went to the closest store, and they were all completely sold out. Well, they were sort of a Black Friday special....
I used my smart phone to check out the store's web page and found that at the next nearest store they had 17 in stock. When I got there, there were 12 fixtures still left on the shelf, so that's what I bought.
I agree that there's a BIG range of prices and quality when it comes to LED lighting. These are LED fixtures. They do NOT hold tubes. So, the lumens rating is for the whole fixture not for one tube or two tubes. The store has a good return policy and these were on sale NOW, so I bought what I could.
When I got them home, I did pop the cover off one to peek inside. It's basically an LED strip directly on an aluminum extrusion which acts as the backbone of the fixture and as a heat sink for the LEDs. Electronics inside are pretty minimal. These run on 120VAC, and have a connector to daisy-chain multiple lights from a single cord. These fixtures are smaller than a typical fluorescent shop light and weigh probably half as much.