I have had one of these mods before, but i cant find it again now that i want it. I am looking for a mod that puts a little sell price in an item tooltip. can anyone think of one and post a link?

Lootlink can remember prices and I believe Auctioneer can display prices in the tooltip also.

If you want the vendor sell price, then SellValue (not on the curse site, but Google will find it), currently version 42. Only shows sell prices for items you've already had in your possession while at a vendor, so it doesn't show vendor sell prices for items you're seeing for the first time.

Hawksy

The informant part of auctioneer will display vendor sell prices in the item tooltip.

KC_Items shows vendor and AH sell prices for items you've sold,seen in AH on any character. (and its mem reqs are much lighter than auctioneer)

ColaLight remembers vendor sell prices for items you've seen the sell price to, as well.
ColaMachine joins a global channel, and shares sell prices to anyone who is in the channel.

The last two are what I would recommend if you want to build your database.. After you've learned 90% or so, of the vendor sale prices, you can remove/disable ColaMachine

all three of those can be found at www.wowace.com