I think this part of the adventure is actually very good for the PCs as far as shopping is concerned. Korvosa is a city in turmoil and chaos, who in the city has the luxury to happily buy and trade expensive magic items anymore? So the PCs will need to search outside the city anyway.
I'll have them join Neolandus on his trip to the dwarven citadel Janderhoff and help him in his diplomacy attempts. Depending on their results the PCs will make the dwarves break off contact with the new government of Korvosa, have them harbor fugitives, have them support the rebels in the city with weapons or even provide military assistance if necessary. While in Janderhoff, the PCs will have ample opportunity to sell AND BUY (weapons and armor and stuff).
The second shopping opportunity presents itself in Kaer Maga, as mentioned by the previous poster. According to the information on this city "Tarheel Promenade is one of the best places in all of Varisia to buy magic items", in "The FLame that Binds" for example.
I'd say that in these troubled times both locations are better equiped for trading than Korvosa, so the PCs can actually take advantage of their trip to the Cinderlands to do some trading.
My players are transitioning into the History of Ashes book and are somewhat furious that they fled from Korvosa into what turned out to be a very small village. They're mad because they're toting a ton of loot from old korvosa and have no idea what to do with it all.
Did any other DM's come up with a solution to this or just tell them to suck it up like I have so far. They have enough magic space stuff to find away to pack it away but it's still just rotting somewhere- and my greedy players want their gold.
Are they really stuck for 2 books?
Yep,
Kaer Magna is the best choice, but Janderhoff and Magnimar are possibilities since by now they probably have access to teleport. Another possibility might include Palin's Cove.
I expect my PC's will turn to Kaer Magna, but if someone wants something particularly special I might try to set up a clandestine meet somewhere that gets interupted or the party gets double crossed by one of their reoccuring enemies. Yep I think that is a good idea!!