Minis, minis, minis... Take care, they're the crack cocaine of the RPG accessories, and for a good while (until the Mrs intervened) I was lost to them.
I'm selling a large part of my collection (lots of D&D & Pathfinder pre-painted) on ebay, three batches (100+ individual mini auctions in each batch) every month. Most of them (90%) have been in storage for the last few years, a lot of them are still in boxes (I have a lot of boxes still unopened), and 99% with their cards (where applicable, see the text of the auctions)- and all sadly never played with.
I'm also selling lots of other D&D/RPG stuff on ebay- I'm emptying boxes that have been in storage, some of them for quite a while.
The Mrs has allowed me to keep one of everything, so I'm still collecting the new stuff that comes out, just selling all the 'spares', instead of putting them in storage.
This month's auctions started on Thursday (auctions start 5th, 12th & 19th)- you can bid and buy all month and then pay at the end with combined postage (if you like). I think they're fairly cheap but have a look around...
Here's the first of them, go here and then look for other items from the seller (goonalan), maybe there's something you like-
They’re also more expensive- with only four in a Booster. Note any mini listed as being used, and/or not in bag, is still in very good condition. The following is a guide to prices-. Small Parcels not exceeding: Length: 45cm, Width: 35cm, Depth: 16cm & Weight limit: 2kg.
Chaos Cards UK especially for the Wizkids Deep Cuts, Nolzur's etc.
Tritex for old prepaints.
Check out Blackwells Bookshop for the Nolzur's; got a great shambling mound there for £4.99.
For masses of cheap minis:
em-4 plastic orcs & dwarves - 21p each; in bulk around 16p each!
Mantic, Warlord and other Not-GW wargames minis manufacturers. Mantic undead are all very nice. Warlord hoplites great in my Primeval Thule campaign.