I've gained my doctorate in Mechanics, so steam engines have been severely high on my wish list. For the few levels leading up to it, I frequently saw one for sale at the inventor's shop in Tarant and that's about it. I used a fate point to pick his chest one night, stole it (along with everything else) and made my first arachnid. Ever since, I have not seen another one available, and it's been about 5 levels worth of playing now. Was that the only one available in the game or do I need to keep refreshing the inventor's merchandise in hopes of another coming up for sale? On that note, is the only way to refresh a merchant's inventory to leave town and come back? Or is there another way....maybe resting/waiting for so long?
The good news is the steam engine does get replaced in the inventor's inventory. The bad news is that it does so infrequently. 10% chance. You can simply wait outside his shop and just advance the time for one day, (after day, after day, after day,...) and run back inside to check. Also - There is one available as a freebe in the shipwreck at Caladon. For the stock game, that's as good as it gets.
I believe they show up at tne Dwarven Inventor's in the Wheel Clan as well, but that's probably using the same refresh rate.