There was a person on eBay that was asking $120.00 for a used 12-round PT-58 magazine. As far as finding a commercial source for on-going purchases of PT-58 magazines, I have not been able to find one as of this writing and I also own a Taurus PT-58 in .380 cal. I wish the picture was much better since I would very much like to be able to buy more magazines for my PT-58.
Keep an eye on gun broker, every once in a while a good deal pops up on them. Most of the time they are way over priced. I have had some back ordered with Taurus for over a year now hoping one day they may get some in. 10 rounders are more common then than the original 12 rounders.
There is currently one auction on GunBroker for a PT58 magazine with a $55 starting bid and another one for a pair of PT58 magazines with a starting bid of $149.00. One problem on GUnBroker is people will price in any sentimental or perceived "rarity" into the starting bid amount. Neither auction is from a seller that accepts credit cards as a form of payment.
Everything for the PT58 is badly overpriced on eBay.
I have found out through a VERY lucky purchase that some of the older 10 round mags can be converted to 12 round because they simply have a spacer attached to the floor plate of the magazine which can be removed. However, magazines like the one below can not be easily converted.
I just received the four magazines I bought from the Gunbroker auction listing I posted above. Seller is 100% legit, received 100% new 12 round OEM magazines for the PT58. Two were still in original Taurus wrapper/packaging. Again, 100% new, no wear or usage marks. Yeah cost was [email protected] but then again they new and hard to find now. Buy with confidence with this seller.