Subject to physically taking it to an MX5 specialist it does look saveable and I reckon a final bill after brakes are done and possibly some suspension sortimg like replacement rear lower wishbones and the odd bit of exhaust and tyres £2,000 to £2,500 would be reaonable.
If you are handy at car sorting and have the time and knowledge and facilities then you may get a good saving on that price.
You do need someone like MX5Restorer or say CBS up in the North West or whoever to give it a good exam as things can get very expensive.
It looks good as a base, get it trailered to the inspection or if you drive it book an MOT to allow you to legally drive the car to the test via a body shop.