I'd expect the reason why some people were umimpressed with $3300 for a 1275 runner is that you don't know just when it's going to need a rebuild as quoted. If you buy it privately, you have no clue of its history and you can only trust what the seller tells you.

Even among Mini owners, not all sellers are transparently honest! If you buy it through an importer, they'll generally give you at least a start up warranty, but, at the end of the day, they're in a similar boat - they haven't seen the history of the engine, so they can't even be sure how long it's going to last, and they're taking a risk in giving that warranty. That's why they'd charge $3300 (plus of course their purchase cost, freight, duties, and a little profit). $3300 from anyone not giving a warranty can still be considered steep - even $3300 from someone giving only a start up warranty - unless you can trust the seller (based on reputation with warranty claims) - can be steep, given a dodgy engine might still start, and therefore the warranty is fulfilled...

That's not necessarily because the seller's trying to rip you off, it's just what can happen! I'd be wanting a couple of months warranty if I were buying a running engine (unless it was very cheap), purely because you can't be sure it's not going to go bang the day after you start it up. And then you've got $3k on top of the $3300 you've just paid out... You could've bought another Mini! And that's why people can be sceptical towards running engines. Even importers can be sceptical, unless their people overseas were driving the car before it was cut up. That's also why many people recommend buying a cheaper non-runner. Better to spend say $4500 (engine plus rebuild) to get something you know will last for ages than $3k for something that might already have done over 100,000 miles (but still runs).
What's the spec of the engine you've got a quote for..? I'm curious about the offset boring...
