with the exception of wool workshops whom is in the 300+ range at all time for whatever reason.
There's a specific reason for that that's pretty technical. So, the price fluctuations of items in the game are mostly determined by their 'supply' and 'demand' values, with the supply values being derived from the quantity of a particular item in a town's market (i.e. the more of that item in the town, the lower the price). Well, the price of an item is clamped to an upper and lower limit depending on what kind of item it is. For trade goods, it is 0.2x to 10x the "base value" of the item, and for merchandise (which is what garments are) it's 0.8x to 1.3x the base value.
What this means for garments is that even as their quantity grows higher and higher in a town as weaveries pump out more and more of them, their price will never fall below 0.8x their base value (which is about 125g on average). It actually only takes a handful of garments in a town for their price to bottom out, so essentially they are always at their lowest price, but since that price is still relatively high, wool weaveries can still make a steady profit from them. Compare that to a workshop like breweries, where the price of beer will continue to drop off more and more as the market get saturated with them (because trade goods' lower limit is 0.2x the base value), which can cut into profit margins much more significantly.
Last year, I made a
post that dove into the price model of workshop items which included some graphs that simulated the price model. If you look at the
graph for garments and wool, it's easier to understand why wool weaveries always make a consistently high amount of money (the red line is garments, the blue is wool). Keep in mind, that post is super outdated, but I think rather than updating it, I'll probably instead create a new thread with all of the changes that have occurred since then.
As far as general advice on how to choose the right workshop, a town's
prosperity increases the demand value of an item as it grows, which in turn increases the price of the item, and is a huge driver in the profitability of any workshops in a town because the price of the output typically increases at a faster rate than the price of the input. If you alter one of those
graphs to use prosperity as the independent variable instead of quantity, you can see how much the expected profit grows due to increasing prosperity (green line).