You’ve never considered that Golf has an actual price to it, while most poorer kids just play soccer with a single leather ball on the street, costing less than a dollar for dozens of kids?
Fred Couples (Hall of Famer) grew up in Seattle, biked to Jefferson Park Golf Course during the summer every day with $5 in hand from his mother, played a round of golf for $3.50 and got a burger and a coke with the remaining $1.50.
Some courses (including aforementioned Jefferson) will have free or heavily discounted rounds for junior golfers after some cutoff time in the afternoon.
$3.50 in 1972 (when Fred Couples was 13) is equivalent to around $20 today. (and $1.50 is now around $8.75)
Lincoln Park in SF charges weekday rates of $13 for a resident junior (or $20 for a non-resident)
Harding Park charges $20 for a resident Junior.
The burger will cost a little more, Harding Park's grill charges $14 for a burger... though Nachos or a Quesadilla are available for $9.
Old clubs are very easy to come by (relatives, craisglist, loaners). The main thing that I feel is being overlooked on this thread is that balls can be had for free, given the child puts a small amount of time in to look for them. Walk along the tree line of any fairway in the world and it will not be long before you've found enough balls to fill your front pockets.