> First you are wrong from the very start.

LOL

> because concert recordings already achieve this purpose

They are quite different, not subtly different.

> because time in the studio is costly

When they do 20 takes and pick the "best", there's always a second "best". It's not like you're starting over.

> and you are not touring or composing while you are doing it

C'mon, a big chunk of the composing is done in the studio. I watched "Get Back" and saw the many variations before the Beatles picked one.

> most would not buy n versions of the same song

Sure, but some would, and that number is greater than epsilon. I'd buy Led Zeppelin variants.

> Producing many different SKUs

Make the small variations the same SKU. Slight variations does not imply that either is better than the other.