if they easily fitted to th 22xx air tube you'd have a larger market but as they don't they'll not fit much without a fair bit of machining
the barrels are just the same as crosman ones (still need machining to fit a 22xx breech)only the .25 barrels were of exceptional quality as they were outsourced to green mountain barrels
i bought a complete one for £300 posted the other year in immaculate condition
if they were p-rod barrel and breeches in top condition £140 each but m-rods have never taken off here and as such not worth a lot to most
price wise i'd offer £50 for the pair as to make them fit anything other than a m-rod air cylinder and valve would take a lot of machining and easier to buy something ready to fit or make from scratch