TS - for the next auction, Saddles or Leather Armor make sense to me.
The current marketplace has a wide gap between Buyers' Bid and Sellers' Ask prices. You have just established an auction price for Cows at 250 ea. (tho I suspect that this is inflated due to bidding exuberance). Both Saddles and LA require Cows. The raw materials required are negligible in cost. So theoretically, these 2 goods should be the cost of a cow plus a premium for factory time. So I would expect a Saddle to sell for 500 (250x2) plus a time premium...LA should sell for 250 plus a time premium. Your auction could give us a clue as to what the value of factory time is.
Using the same logic...most of the cost of a cow is the time premium.
At level 1 factories, production times are:
Cow 1:06:51 (67 minutes roughly)
Sdl 1:20:00 (80 min)
LA 52:32 (52.5 min)
So time is priced at 250 gold = 1:06:51.
Thus, a Sdl should cost 2x250 (2 cows) plus time premium of 298 (80 min - 67 min = 13 min/67 min = 19% more time for Sdl over Cow...250 Cow x1.19 = 297.5) So total expected Sdl cost = 798 gold.
Same process for LA: time premium 52 min - 67 min = -14.5%...100%-14.5%=83.5% x 250 = 208.75. Cost of Cow = 250 plus time premium 209 = 459 total expected LA cost.