I currently have about 70k gold and have pretty much stopped collecting loot because I have no use for money except to buy training. AFAIK, the merchants never seem to have weapons or amour or other items superior to what I am finding or making using a good something plus a sigil stone or using an enchanting altar.

Am I doing something wrong to have not found any item (save one, a staff called something like Aphoresis) worth buying at merchants? My toon is a sneak archer. Aside from arrows, I can't find any but the most low level bows in any merchant I've seen.

There is another thread on this topic a few thread away from yours that you might be interested in reading: http://www.gamesas.com/topic/1475794-spending-gold/

In short, there is not a lot that can be done. You don't say if you play on PC? If you are on PC there are mods that help somewhat. If you are not on PC, you might try a few of the suggestions in the thread I linked you to.