Well 'Catalog' is a view so you could always duplicate it and change the regular price field to the wholesale price field. Then expose the views depending on roles. That's the easy part.

Actually charging them the different price requires an extra module and honestly I don't know if it exists in Commerce. I know the old UC module I used for this was http://drupal.org/project/uc_price_per_role. If you can port, that would probably be the route to take. With that module you can ignore the first part of this post since it exposes the different price automatically.

Alternatively, you can try using rules to change the price of an item but only if the wholesale price is a uniform flat dollar discount or percentage discount. Anything else and you probably won't be able to do it with rules.