Handirifle,
I've purchased used barrels from $100 to over $200. So what's a good deal is subjective. The $100 ones I got shoot just fine, but they had significant finish wear, a rust spot here or there, frame rub marks, etc. Also, you are in CA I believe, and typically it's a high cost state to live in I believe, so that will affect prices. Certain calibers are pricey too, as not many were made.
If it shoots well, I say you did just fine. Could you have done better? Probably, but the really great deals aren't that often. Good caliber, can shoot 357 Mags for practice, though to minimize leading (if you are shooting lead), I would make up some 357 mag level loads in 357 max cases.
The 375 Win isn't that bad, it's a 14" Bull with a Scope. I think there were a good number of 375 14" pistol barrels made, as I haven't seen the prices get too crazy on them. My used 21" tapered 375 carbine barrel I had to pay a pretty good sum for, though, no deals on those. I like the caliber despite it's being pushed to the backburner due to the 375 JDJ which is all the rage now in the Contender it seems. I'm sticking with my 375 Win.
Keep an eye out, you may just find a 375 Win Barrel for sale on Ebay or here.