>Would have hurt paul financially, of course, but far less than it probably has over the last 20+ years.
Maybe he felt maximizing his riches and spending like a loon wasn't within his interests? Or that this wasn't a good investment? I think its obvious now that the post-ipod world and post-baby boomer nostalgia period, etc means that music monetization for oldies is high, but at the time, records and tapes ruled, and their sales weren't exactly inspiring for 60's rock. Disco, New Wave, Punk, etc ruled at this time and the prospect for a big Beatles fan revival seemed low. The new CD format ramped things up a bit and obviously the digial music revolution happened, but to a conservative investor in 1976, well, those would have been very risky trades.
Its also worth noting that ATV bought the rights from Northern Songs for $17m in the late sixties. So just a few years later the negotiate priced went over $40m? Triple the price? Of course, Yoko and Paul balked. In 2015 dollars we're looking at close to $150m for publishing rights. That was unheard of.
Lastly, this is just publishing rights. My understanding is that other royalties were quite profitable for the remaining Beatles and their estates and getting back publishing rights wasn't a high priority for them. All this hand wringing is interesting, but it didn't stop them from getting incredibly wealthy. None of them were remotely in the poor house.
Of course, in England, the taxation for the top earners was something like 80% (more?), so amassing a fortune meant losing all but 20% of it instantly. This probably helped Paul, a UK citizen, make his decision to not bid large on a potential big payout. Lets say he bought the catalog for $50m in 1976 or so and his net worth at the time was $200m. Now he's down to $150m and lets say that investment brings in another $100m in twenty or thirty years. Great, he's now back up to $170m post tax. Still a $30m loss.
To get (or recover) something of business and sentimental value and have it 'in the family' so to speak. Paul's no dummy, and understood the long term value of publishing rights for music from decades earlier. Could he have predicted digital music? No, but regardless of music format, the Beatles were (even by the 80s) an extremely unique entertainment entity, and weren't going away.
It was a decent amount for either/both of them, but wouldn't have bankrupted either of them. It actually seemed more of a struggle for Jackson to pull things together to make his acquisition happen than it might have been for Paul.
> some unrealistic gentleman generosity
L&M seemed to do just fine with a gentleman's agreement between them for several years re: songwriting splits.
They don't own them up front in the first place. No doubt some labels negotiate that as part of a deal, but they're separate domains to start with.