Wow...what a question - I've been playing since I was 12 (40 years +) - break it down like this:
Age 12-17 - not much, and not my money anyway - Parents. My 1st set of clubs was a "cut down" set from my grandfather...then I distinctly remember my first purchased set - from Austad! I can clearly remember going thru that catalog - pretty sure they were RAM - Gene Littler. Can remember at the start I had just 2 woods + 5,7,9, PW & Putter - 7 pc set. And then saving my money to add the 6i & 8i...used those clubs all thru HS. Maybe the set cost $200? Played 90% of my golf at the Univ of Md golf course for maybe $5 a round? (my mom was a university employee)
Maybe ave of $100/yr = $500
Age 18-22 - college years - as i recall I could get a summer membership at Univ of Md (unlimited weekend golf Mem Day thru Labor Day) for ~$100? And $25 for a locker? I kept me clubs there and rode my bike to the course (no car)...would play 18/36 holes 2-3 times a week - by then my brother was in the golf biz (working at Manor CC) - so got new clubs "at cost"
Golf was secondary - I was on the men's volleyball team and played indoor & outdoor volleyball pretty much all year round.
Ave= $250/yr = $1,000
Age 22-28 - Young Adult years - didnt play nearly as much. Working my a** off...travelling. Playing volleyball...maybe after 5 years of work started to get back into golf with some co-workers playing.
1st set of "tour" clubs - Tiltleist Box Blades I think - still hitting Wilson Staff persimmon woods
Ave $400/yr = $2,400
Age 28-36 - "serious golf" - not married yet...out of volleyball. Joined a club (Mont Village) - that was $5k initiation + ~$300+/mo so easily $4,000/yr
Got handicap down to 1.6. Playing lots of State/local tournaments - trying to qualify (unsuccessfully
) for national events
Advent of "metal" woods...Irons were Tm Tour Preferred...1st "travel" golf - played in Hawaii, went to AP golf Academy @ Innisbrook for a 3-day school
Easily ave $6k/yr = $36,000
Age 36-46...married...quit club (boo hoo)...2 kids...back to playing 10-20x / yr...shoulder surgery (old volleyball injury) kept my out 14 months in 1 span
DCI Irons - played for 12+ years. I do go thru drivers - at least 6
Ave $1,500/yr = $15,000
Age 46-present (53)...kids growing up...son plays....still no club member, but playing 20-25x per year. At least 1-2 golf trips/year 0- including overseas. Paid most I ever have for rounds of golf - $250+ to play RCD, RSG
$2,500/yr (includes buying junior gear, etc) = $25,000
So that's a total of $80,000
Probably low estimate...although I'm not a big spender on gadgets, etc.
For example, in 40 years I've basically only used 4 putters (A wilson 8812, and since then 3 version of Ping Ansers)...and 5 sets of irons? But have gone thru minimum 15-20 drivers...and lots of wedges