A car with years and years of patched up repairs will be quite close to end-of-life. Botched repairs can make things worse. Rust repairs can fail after 5 years. Check carefully cars up for sale, with owners boasting of spending thousands to have it done “properly”, only the repairs were done 10+ years ago. I remember distinctly when the first owner appeared on the UK MX5 mailing list with a required sill repaair, and it was about 2000. Mk1s started to rot out after about 10 years on UK roads. So for imports, that clock started from the day they were landed. eg. a 1990 car imported in 2000, probably started to show signs of rusting in about 2010, and those repairs, if done to the very highest standard, might need looking at again in 2020…
This would be considered a bargain:
But £2k will also net you an early Mk3.
Cars repaired “properly” will likely be out of budget. But sometimes there are bargains; see the ads here, but also if you join the Owners Club, the club magazine will incude small ads for cars whuch never appear online.
Besides rust (and Mk2s will have other rust issues), you need to check the car for accident damage (its a sports car). And that damage might be a bit more than a dinged wing. This video is about a car in for usual rust repairs that had a history of multiple accidents:
Roofs; ones with a shredded top will more likely have rust issues. New roofs are ~£300. Soft tops have a limited working life (5-10 years).
Mechanicaly, early cars (1990) had issues with the crankshaft. Later cars might also have problems with the crankshaft if the timing belt was botched.
Oil leaks; fairly frequent on these cars.
Older radiators can fail. Oil leaks on a 1.8 can lead to catastrophic failure of heater hoses. Both can lead to overheating. The engine is robust, and an alert owner can save the engine. But a less alert owner may en up saddled with a car with HGF issues
Electrical issues; the early cars are old cars now. Things like wiper and headlamp motors starting to give problems. Replacement factory parts can be expensive new, or NLA (there were 3 different wiper motors on the MK1, and they are not interchangeable). Availability of used parts is not like it was a few years ago, when there were reliable mainstream suppliers who were well stocked, such as Autolinkuk.
There are bargains out there, but be prepared to travel, and be flexible. Don’t discount an automatic version, because they wil be cars that will be less messed about with. The conversion to manual is fairly straghtforward, and 5-speed gearboxes, because they don’t go wrong, are cheap (sell for scrap weight). If a 1.6 auto, on paper it will be 4hp own on paper, but you won’t notice the difference on a 30 year old car.
Do your homework on insurance implications if the car is a grey import (Eunos, Eunos Roadster, Mk1s with a square rear plate). The insurance might be twice that of a UK spec car. All Mk1 autos are imports.