Shops really aren't worth as much these days, I`d have thought this is very much a buyers market. But does the shop have flats over it ? That changes the business proposition markedly because they'll probably be much more easily rented out, which increases the value of the shop but also the income you`d get from it.
When I was considering the pros and cons of shutting down my business I more or less assumed I wouldn`t be able to rent out the shop (I own it), after all there are so many empty shops about. That said my shop is quite big and next to two fairly busy bus stops (one in each direction) so maybe I could rent it out though it might take quite a long time to get a tenant. Fortunately for me my shop has two flats over it !