I think you should make your own! You save a bunch of money that way. I plant mine with regular good draining cactus soil, then put rocks and what not on top

I would research soils. There is a lot of different advise on here about soils. I would also get plants that are well matched in temperament. separate between winter growers and summer growers and also some cactus take less moisture than others. Especially if you are mixing cactus and succulents. I have a lot of fun with decorative rocks creating changes in soil level. It is so much more fun than buying a dish garden. The store just mixes them willy nilly and then they die. You can do better.

Yeah i recomend researching the cacus needs to ... before i knew much about them i put a melocactus with some other things ... and since they need water in winter it kinda ... died O_o i have 6 cactus gardens and they are the number one thing i enjoy making :)