Mrs. PBJ; there are a number of websites that list the suggested pricing... Personally, I would have a hard time parting with my ponies, but more power to ya!
Some people sell in bulk lots, (like 20 bucks for 10 ponies), but I don't think that good looking, good condition ponies should be sold like that.
If you have the yellow pony with the parrot on her butt, you've got 300-500 dollars in your hands... That's Mimic (image at bottom of post)
Take a peek on Ebay... just type in my little pony, and do a price search highest to lowest.
If you still know which accessories go with who, all the better!
http://www.kimsites.net/dreamvalley/index.html <--- will help you find the names of your ponies and their accessories.
Some people trade on the MLP trading posts...
http://www.mlptp.net/forums/
(You can get a better feel for demand there, as it is current)
Here's an old pricing guide: I'm sure numbers have gone up...
http://mylittleponycollector.com/links/frm_pricing.htm
Intact Flutter ponies get a good price, as their wings were so delicate that most kids broke them...
You may decide to become a pony collector again! Sounds like your collection is almost complete (I think that would be SOOO cool):shock:
Your collection would be all G1 ponies... the ones being sold in stores right now are referred to as G3 ponies. G3 has a sleeker body design; G1 ended around 1992-1993.
Yours definitely have value!
The Elusive Mimic!!!