And although it's anecdotal, a local highly respected engine shop remarked that it's seen quite a few major problems (e.g., cracked journals) on over-TBO O-200s.
I have my own anecdotal, random-sample-of-one, but when my O-200 was disassembled after it's second run to TBO (at least, according to the logs), a cracked crankshaft was found.
I don't know how long the crack was there, or how short before it would have 'notified' me through other means, but there was no indication prior to disassembly.
Sounds like your thought process was very well considered. And you are fortunate to have the means to not let finances color your decision too much.
