Are all stand along phono preamps both MC and MM? If a person knew they were only going to be using MM can a MM preamp only be purchased, perhaps even at a price that reflects it not having the not necessary MC electronics?Most inexpensive phono sections are MM only. You need more gain and a good noise floor for LOMC cartridges- and that costs more.
One other thing about a good phono stage. A good one will exhibit less ticks and pops due to better RFI resistance and good overload margins.