I have alot of items but most of the shopkeepers dont have the money to buy them

If you do all of the special jobs for the thieves guild, you get access to vendors who have 4000 gold in almost every city, without putting any of the perks in the speech skill tree. You can increase it further with those perks if you wish.

Secondly, if you're only a few hundred gold short, you could allways just buy arrows and junk, giving your gold to the vendor so that you can just buy it all back when you sell your expensive item. You can then sell that junk you bought a little later on if you want.

EDIT: Slightly unclear.

You're going to have to go from shop to shop in order to sell your items. Every shop will give you the same price whether you're buying or selling and it will take a day or so for them to get all their gold back. The higher your speech skill, the better prices you get. There is a perk under Speech where you can invest gold into any shop and it will permanently increase the amount of gold they have to barter with.