Well as I said before it just all depends on how common the mags are. The really popular platforms have plenty of aftermarket support. Hell even Magpul makes Glock mags now. But some pistols just have expensive mags. Most Taurus factory mags are high. I assume Springfield and Smith factory stuff is the same.Usually the only firearm that come with 1 mag are either low budget or milsurp
The no mag ones are weird though but then the seller might sell the mags later for extra dough