Hamish
I take your point, but
One of my group flew once a month only because of similar issues, and never really made the best of his membership. I watched as his airmanship fell through the floor and he became positively dangerous.
He left the group because he couldn't afford to be a member, even though it cost him less than flying club rates.
I now find he is flying at a local club, once a month for 1/2 hour or so, paying for his flying on a credit card.
Apart from the problem of repaying the card payments, he just has time to leave the circuit, bang in a few landings. In the past year he has not landed away or even had to change radio frequencies.
Yes, he is still getting airborne, but I'd contend he'd be better off giving up for a time until he can afford to do it properly and, yes, safely