I'd say 100 pounds ($138 using today's exchange rate) is a good price for any rideable bike in the global market we have today, yes. Your rear wheel will be a more definitive clue as to the identity of this bike. If it has a freewheel, then it's almost certainly an Escape 3. It would have had a Shimano freewheel from the factory, and it would me marked with a large white part number, such as "MF-TZ31" or something very similar to that. Shimano freewheel part numbers start with "MF". If it's a cassette, it may have a part number that starts with "CS", such as "CS-HG200" or similar.
An
Escape 3 had a 7-speed freewheel and Tourney components with the bright crankset arms. The
Escape 2 moved up to an 8-speed drivetrain with a cassette and black colored crankset arms. The
Escape 1 moved up to a 9-speed drivetrain.
One curious thing I see is the seat post clamp area. It looks like there's a black clamp or mount down near where I'd expect the seat post collar to be. Then,
above that, there's a silver anodized seat post clamp. What is the lower clamp? Is that one designed to be able to mount a rack, with its two rearward extensions? If that's clamping the seat post into the frame, then you wouldn't need the upper, second clamp. If that upper, second clamp is clamped around the seat post itself, acting as a down-travel stop for the seat post, and the lower clamp or object is
not clamping the seat post into the frame, then that's not correct. You'd want to reconfigure it so the seat post clamp clamps the seat post into the seat tube extension of the frame. I hope that makes sense.