When I upgraded to a newer version of the OHRRPGCE, my shops were all wrong! What happened?
There was a known bug in Serendipity where the shop data was expanded incorrectly, causing shops to demand crazy trading deals, like 61 Thingamabobs for 1 potion. This bug only affected games that were not upgraded in CUSTOM.EXE, but instead played directly in Game. This was fixed in Tirgoviste, and if you are still experiencing it, you need to upgrade to the latest version.
What, exactly, happened?
To accommodate multiple trade items (like 2 Emeralds and a Ruby for a Sword, as an example), we needed to make more room in the Shop Item lump. Basically, for each shop item, we copy the data over a bit, so there's more room.
However, we forgot to shuffle over the item data in GAME.EXE as well as CUSTOM.EXE as each is loaded into memory instead of simply making the item array bigger to accommodate the new data. So item data overlapped, and item names and whatnot became the new values for the extended trading options. Unfortunately, testing failed to notice this.