You win some and lose some I guess.
Does common stuff seem to turn much of a profit compared to rarer cars?
To me it would seem like a catch 22. You might not get much interest from overseas buyers so you'd get the car cheaper in the first place, but you'd have to sell it cheaper because the public have a lot more (non Cat C/D) cars to choose from?
Yeah you've just got to be really careful how much you pay really. The only cars that seem to have the increased price hike from the over seas buyers are the more rare or expensive cars so best to stay away from them for the most part. But then somtimes the easy reapair catD KA's and the like attaract a lot of attenion also because your average Joe with a spanner set fancys buying it and fitting a new wing and headlight and getting a cheap car for his daugther! You've just got to look at each auction for these cars on an individual basis really.
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Looks like you've got access to garage facilities, I'd be tempted to spend a grand in parts on it (suspension bushes, shocks, cambelt etc) and do the work myself to get it spot on then run it as a daily driver.