Will you be mobile?
Yes, I'll have a car
OK!
Dartmoor could fill a few weeks on its own, plenty of the Tors are easily accessible from the roads, as are a lot of the pretty valleys and bridges. Can't remember which number OS map covers it - it's worth getting the one with the yellow or orange cover. (Explore map numbers... OL {Outdoor Leisure}28 for Dartmoor, 114 for Exeter and the Exe Valley, OL 31 for Torquay to the Exe Estuary and OL 30 for the stretch of coast to the East of the Exe estuary. OL 20 covers the South Hams, another beautiful area, best visited in autum/winter when there are fewer tourists blocking the roads...)
While you're in the area (Devon), it may be worth a trip to Brixham - specifically Mifsuds, as long as you have plenty of space on the credit card and spousal permissions to use it! Have a look at their ad in AP to get an idea of their prices and stocks. In Exeter itself, we have a Jessops, a
London Camera Exchange and the Devon Camera Centre. The latter 2 carry some 2nd hand stock that could be worth a look at if you're shopping. There's also Camerex but the opening times are rather erratic and it's well out of the city centre. Since it's that time of year, there's late night shopping on Thursday nights until the fat bloke in the red suit's done his stuff...