My local restore used to sell commercial lighting stuff, however, the manager of the store decided that the store would become more "upscale" and tossed out and stopped accepting commercial stuff and upped the prices of everything else. Also, all the staff quit, which really sucked because I used to get some cool stuff for free, as they would set aside loose stuff they would normally dump, which normally included a lot of unboxed incandescents, CFLs (including a GE Compax CFL), and LEDs (including a bunch of older LEDs with chunky heatsinks).

The Goodwills in my area are not bad (when they price things reasonably), as commercial stuff pops up in them from time to time, as well as NOS incandescents from the 2000s/90s/80s (I've gotten most of my NOS Tungsram and GTE Sylvania incandescent bulbs from goodwill). Though, the main place I've been having good luck with as of late is Savers, where I have found a fair amount of HID stuff (including these GE 70w HPS floods). As well as other cool stuff.

 I just bought a modern incandescent posttop for $5 !  Photos soon .

My restore currently has a lot of GE, Philips Alto and Satco T12 fluorescent tubes. Looking at the label on the GE box of tubes, they were probably all donated by Lowe’s.