I would love to use pumice but, I don't want to PAY for pumice and perlite works just as well.
Luckily, cactus aren't real picky as long as certain criteria are met: fast draining and fast drying. A bag of Miracle Gro cactus soil and a bag of perlite cost me maybe $10. Mixed together, I can pot a lot of plants and the cactus don't seem to mind how much or how little effort and money I put into their repotting.
What soil or mix you use to pot (unless its something heavy and non-drying) isn't as important as the care you give them once they are home.
