Hi matey , ive had more than my fair share of classic minis myself , still regret sellin my cooper sport 500 (in tahiti) and my mk1 mini too ,
ive got myself a mk1 gti id say check the wings , bootfloor , inner wings , then there is crash damage , mines in the project section so have a look there are plenty of pics of rusty parts , as for how much to pay , ive no idea mine was cheap as chips ,
welcome to the site