Try something like this search (on ebay):

star wars vintage moc -votc -otc -saga

(Leave out the 'moc' if looking for loose figures)

Be aware that many are selling recards (figures in reproduction packaging), so be aware, and check the small print for words such as recard, replicard, reseal etc. They can still look good, but prices should be much lower than with original packaging.

If you are interested in starting a collection, read up on the figures and variants on places such as these:

http://www.rebelscum.com/vintage.asp

http://theswca.com/index.php?action=disp_category&category_id=421

When starting out, the cheapest ones to get are generally the ROTJ and Trilogo ones, the more expensive and rarest are generally the SW and POTF lines, with ESB somewhere in between.

Common ones which can usually be had pretty cheap are Ree Yees, Klaatu and Rancor Keeper.

Good Luck!