Second hand set of clubs from the charity shop £15, bag from same £5, and practice on the school field after the kids have fucked off home, £8 a round at my local ancient uncared for site... OR £2K on clubs alone and £100 per hour lessons, sky's the limit club fees etc.
I use the same DAM rod that my grandfather bought me for my ninth birthday, along with the tacklebox and seat that my dad got me for he same event. £150 a year ticket at one of the county's best waters. Or you could do marlin in the Caribbean and pretend to be Hemmingway for Christ knows.
Anyhow, airsoft. Like George I play once a month but March to October filmsim or milsim (350 mile round trip so £80 diesel plus £75 ticket). Skirmish a few times in the winter. Much prefer to get away properly once a month and truly unwind, but then Mrs TPH travelled a lot for work in her earlier youth, so family hols are not required, and since we play together with our lad, and sometimes our daughter, it is family time.
Leaving the heavy theory out of it. If you decide to learn new lessons when undertaking the same task, you'll get more out of it. Apply it to hobbies and they don't get stale. Complex airsoft games employ so many skills that I doubt I've enough life left to exhaust them even if I did develop them.