Cloth bolts aye 350 gp a bolt has been the norm.
The following were pricings on the crafters of Siege forum *recently*
I will just copy and paste those here for ya.
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I've not kept up to date on this. I'm thinking that leather should now, after the BOS changes, be selling for prices something like this:
Regular: 25 gp
Spined: 35 gp
Horned: 50 gp
Barbed: 80-100 gp.