First of all, I'm more than happy to admit I'm a hoarder. Hey guys, I'm a hoarder... But I'm finding that my bad habits are being reinforced because I can't seem to find anything to spend my hard earned cash on.
I buy destruction spells that I'll probably never end up using (because I like having a big list of spells I COULD use) but besides those and training (which I don't really like doing) I haven't found anything to really spend my cash on.

Maybe I just haven't found the right vendors yet?

I assumed the dude at the Skyforge would sell the best armor/weapons and the people at the College of Winterhold would sell the best magical gear... but so far I haven't found anyone who sells armor/weapons/trinkets that are better than what I've been wearing since lvl 8.

Any suggestions (as spoiler free as possible) would be fantastic.

Thanks so much guys.

Dark

I generally don't know of a single merchant that is particularly good, but Solitude is a great place to sell things, especially if you have the perk that lets you sell anything to any vendor.

From the gate there is a clothing vendor, an alchemy shop, a general store, a blacksmith, and a fletcher. And at the palace is a court wizard with a wide enough selection. And for cheaper goods there is a market of some crappier vendors.

Also, as a bit of advice, if the vendor doesn't have enough cash for your big ticket items, buy junk from them. Spell tomes are a great way of carrying value in smaller more liquid goods that can be offloaded to cheaper vendors.

You lose a bit of money in the long run, but over time you can clear out your inventory of "useless" goods. Also, crafting is a great way to sink money on this (e.g. buy all of their crafting mats/ingredients/soul gems, and sell them your looted weapons and such).

Hmm, thanks for the response Kom! What I'm really after is a vendor or two that sell 'unique' items, or items worth buying. Not necessarily someone willing to buy my stuff. Basically just looking for weapon/apparel upgrades from a vendor instead of just from dungeons/quests.
I remember in Morrowind/Oblivion some of the best loot was obtained from vendors (albeit, quite expensively)

Well, in that case, the clothing shop at Solitude is still pretty good for having random jewelry that provides reasonably OK buffs. More importantly, its a great place to find effects to disenchant for my "custom" gear.

I have the same problem as you, 70k of gold ready to spend but there is nothing left. Houses and horses already bought and spending money on leveling is kinda lame. So i started on decorating my home with gold/silver and quicksilver bars just a pile that is slowly growing. I was also wondering if i could refill the thieves guild vault with gold and jewels but i dont know if the items will stay there forever just like in your home?