Depends on how much cement you plan to mix. A cement ransom can only mix so much concrete as opposed to 5 guys in an open area. And you would still need to move the concrete unless your area to be paved is near a flat area where the ransom could be rolled up next too.
Too many small cement providers to use a ransom.try rbmr services .. Don't know their no tho. Also redimix does small batches or minimum order .. Try calling around you may be surprised as opposed to getting a few guys and doing it yourself