Been playing for a couple hours and I recently joined TDB. Problem is the merchant there hates me for no apparent reason and wants to buy my items at an extremely low rate. Where can I sell my valuable equipment for a far price? Thank you.

M'raaj-Dar has a very low mercantile skill of 6, so you get a better deal that most merchants regardless of disposition. However he doesn't have a lot of coin (400).

If you have Frostcrage Spire (Wizards Tower), you should look at Aurelinwae, who also has a mercantile of 6, but a lot more coin to barter with (2000).

If you don't have that plug-in, go to Varel Morvayn in Anvil. He has 1200 gold and only 40 mercantile.