Flat roof Question

[Taylor C]

I have a unit with a flat roof that wasn't done properly. There's a leak in one spot, and bubbling in other areas. I think it's rubber.

A local contractor says the top layer should all come off and then depending on the condition of boards below, that may need to be ripped up, joists checked, new carpentry, new insulation between, vapor barrier, etc. Lots of material and lots of labor.

With the potential of doing a major reno in the next 10 year (it's happening up and down the area), what's one to do to avoid spending $ on a new flat roof that will last another 20+ years when it will just get scrapped?

Tin roof with a slight slope, what about framing issues? Just trying to think out of the box.