Purchasing doujins!

Suggestion can we get a way to purchase doujins from comics? Example Refined Senpai 2 came out and i'd want to buy that along side refined senpai 1! Or can we have the ability to purchase a whole Magazine.

That's eromanga from the magazine. They would never piece them out. Magazine vol sells maybe but I'm not sure if legally could. They was kicking around a best of version but haven't panned out yet. Best bet is the tankobon if that artist gets one.