There are three places listed on Airbnb near East Prawle, South Devon, priced £30/40/50, ticks most boxes, except riding, of which there isn’t much. Two good pubs, one in East Prawle, and one in Beesands, with two more a bit further away in Torcross and Slapton village.
The Cricket in Beesands does really excellent food, and does b’n’b, but might be a bit more pricy that you’d like, last time I looked a room was £65/night.
Outstanding walking all around there, though, I love the area, and I’ll be back down there in a couple of weeks time, but camping down near East Prawle, looking out over the open sea.
Looking further afield, there are quite a few on Airbnb, but bike riding in that area is fairly constrained, I think, not much off-road, and on-road the lanes and even A-roads are really very narrow and winding; driving from Dartmouth to Kingsbridge, the best bet is to find a bus to get behind, because everyone else has to get out of its way!
Otherwise, you’re constantly having to stop to give way to oncoming vehicles, because there are so many pinch-points, and that’s fairly common through Devon and Dorset.
The last time I drove down to Charmouth, I drove for nearly nine miles behind a tractor and trailer, because there were no places for him to pull in, and no places to overtake.
