I dunno if this is common knowledge or what, but I figured i'd share this.
So I went to Lowes looking for a few things, including the cheap little plastic seedling pots most places carry.. And after a thorough inspection, found out Lowes didnt carry them. So I grabbed a big bag of sand and some other stuff in the outdoor garden center and went to the counter outside to pay, Where I then saw a few big plant racks covered in used pots and trays, with a sign that said "recycle your used pots here". So I told the lady at the register "Hey, I was looking for those kind of pots, but looks like you don't carry them?".. The lady said "Yeah, sorry.. But if you want some go take as many as you want, just remember to bring any pots back to recycle once your plants outgrow them". So I was like SCORE! And grabbed a few stacks. Just got done cleaning them all in soapy bleach water and counted em, ended up with 35 free pots, ranging from 3" to 10-12" big rubber ones... So yeah, I dunno if this is a regional thing, but might be worth checking your local Lowes for used pots if you're in need of some.. Definitely saved me a few bucks.