Wordpress MYSQL how to group 2 fields in a table?

Question

MySQL

Wordpress created 2 additional fields for each post post, post_meta Price1 and Price2... you need to group them and display the result as an interval, something like this:
100-500 rubles.
500-1000 rub.
and so on...
there are no problems with grouping one field, but how to do it for two meta at once?