Never really got "into" it, but have scored a few things:
3 HP Laserjet III's- All of them had some sort of feed problem, but a $15 (ea) roller kit fixed. Use them for my "loaners" (not unusual for me to get called "My Printer Quit, and I've got to get the invoices/Statements out today!")
2 Apple Laserwriter II's- once again, had some problems. Used for spare parts to fix the above. BTW, these are all from gov't office!!!
Deals close to dumpster Diving:
My first scanner (and still preferred for B&W work) HP Scanjet Plus- cost me a whopping $2 at a city auction
Helped a buddy toss a ton of 13" monitors- did find a couple of 17" that needed a fuse replaced. Due to the way they have things set up, he couldn't buy them- but I could !! $3 apiece- sold him one (after fixing it) for $10