Item Costs

Chapter 4 of the Level Up A5E guide (starts at page 308) contains various item prices. Unless the DM says otherwise, it can be assumed that those prices are what things are going for in Icewind Dale.
In addition, your characters feel that the prices found on this guide should be generally acceptable. Although if there is a discrepancy between two different prices, the Level Up version is correct.
https://dungeonmastertools.github.io/items.html