Are you concerned about picking the right combination and numbers? Or are you looking for a discount on numbers? Most vendors will offer a discount on a sizable cleanup crew. DIY cleanup crews are better imo, but I'm picky about what I put in my tank. Most vendor created cleanup crews will include both hermits and snails which is like putting pedophiles in an elementary school.
Not to mention they will sell you a 50 gallon cleanup crew that is really sized for a 300 gallon tank! More
!