is there a good local shopping area not too touristy nearby the rci cruiseport
When you come ashore, you'll see the usual sort of of touristy shops in the port area.
If you leave the port area, you're in a residential area called Casitas. There's a couple of grocery stores, a pizza restaurant, a couple of hotels, a cafe, real estate office, a pharmacy, etc. It's not touristy, and not much in the way of souvenir shopping here.
If you continue to the Malecon (another couple of km), there are lots more shops, but tourisy.
Mahaual is a touristy place, If you want non-touristy, you'll have to go to Chetumal or Felipe Carrillo Puerto, each about 1 to 1.5 hours away.
It's an easy walk from the port area to the residential area, Las Casitas, but to continue to the Malecon, it's better to get a taxi because the walk is along the highway and there's no shade or sidewalk.
How much would a taxi cost ?