Depending on what the known MPU issue is, I would go 700-750 pretty easy. If the known issue is an easy fix, then I would go even more.
I paid 900 for mine 7-8 years ago. It had lots of little issues, overall a nice playfield, except for a moved post and extra hole on the playfield and a close to perfect backglass. And that was 7-8 years ago. It is one that will never leave, even though I don't play it very much.
"Little surprises like the capacitors don't bother me too much. It is big MPU surprises that can give me headaches.