This includes:
1. Shopkeepers had ridiculously small amounts of gold, meaning you could only sell items for a maximum of 2000 at most stores. Have you ever found some awesome weapon that was worth a lot, but could never get that much for it because the merchants had little money? This completely destroyed buying and selling in Oblivion IMO.
2. Trying to sell things in bulk was time consuming, and rather annoying. If you have 500 arrows you want to sell, but the merchant only has 2000 gold, you have to scroll all the way to the beginning just to make a transaction. This wasn't a problem on PC because you could simply drag the sliding bar, but for consoles, it was painfully slow.
Some solutions that could be implemented are:
1. Give NPC's unlimited amounts of gold. I mean, why not? They theoretically already did in Oblivion, it just restricted how much you could trade at a time. This will also allow you to get full price for some of the more expensive items.
2. Allow us to simply select the number we want to sell of an item by typing the number in on PC, or having slots for each digit and you could manually input the number you want to sell. If you can't understand the latter part of that, simply imagine a slot machine, with each image being replaced by a number. If you wanted to sell 143 arrows, you would select the first slot to be a 1, the next to be a 4, and the last slot to be a 3.
This wraps up my thoughts on buying and selling. Is there anything else you felt was wrong with buying/selling, and if so, how would you fix it?
P.S. I have never played Morrowind, so I am unaware of how trading was done in that game. Was it more efficient?