Brew isn't there some innate oddity in the music business that means bands earning are sort of log jammed for the first few years of their careers. Wasn't it U2 who had done many tours and sold millions of LP's had to wait until 1985/86 due to Island waiting for a movie investment to come through before paying the band. (don't quote me but that seems to ring a bell in my old brain) Also weren't many artists even at the levels of Plant, Bonham, The Beatles The Stones et al on salary for years. So even at that point maybe The Beatles were not seeing much return for their work.
I think I read Brian finally ended up paying for both guitars. Also as late as 1965, when they had tons of money, they still had to go thru Brian if they wanted anything. When they wanted those two strats (1965) they sent Mal over to Brian's to get the money for them. And Brian told Mal to get two of the same color, he didn't want any bickering. lol Of course by then they couldn't go anywhere and poor Mal had to be their goffer for just about everything. Also later on guitar companies would just send them guitars for an endorsement. I don't think Paul ever paid for anything. lol
bands earning are sort of log jammed for the first few years of their careers
At that stage, The Beatles would have been paid in cash for most of their gigs. It's true that royalties for recording could be tied up for years, due to various "creative accounting" practices by the big labels.