After the viewer update, we were made aware of a critical bug that may affect vendors in a most unfortunate way – there are some subtleties involving linksets and permissions, so please visit our public Issue Tracker for a full discussion of the matter.
In short: imagine you have a number of vendors out, all set at different prices. You take them up all at once, and they are taken into your inventory as a coalesced object – meaning, they are all stuffed together as one. You then take them out of your inventory again to set them up at a different place, and all your vendors will be set at the same price.
We strongly recommend that you for now abstain from taking up multiple vendors at one time, rather you should pick them up one by one if you’re planning a move or redecorating your shop.
Our Developers Team is aware of this bug, which we have classified as a showstopper, which means it’s *really* high up on our list of things to fix. In fact, they are working on a fix as I write this, and we hope to be able to roll it out very soon.