Of course, I didn't factor in the cost of flights and hotels when attending a GP.
Mind you, if one did a matrix "cost/duration/entertainment value", I am not so sure where F1 would come

Event Duration Price Range
Formula1 GP 3 days $142 – 700
Daytona 500 1 day (?) $170 – 1,235
Indy 500 1 day $100 – 780
Nascar 1 day $85
Boxing: Mike Tyson 1 evening $100 – 2,500
Superbowl XXXIX ½ day (?) $1,200– 6,000
Golf: Augusta Masters 4 days $3,500
Gymnastics 1 day $385
Horses: Kentucky Derby 1 day $375 – 1,300
Olympics:
Athletics ½ day $85 – 450
Soccer 1 match $80 – 180
Sailing 1 day $385
Opening Ceremony 2 hours(?) $1,295 – 2,080
Tennis: US Open Final 1 day $2,025 – 2,500
Others:
Samba Parade, Rio 2 days $500 – 3,100
Andrea Bocelli 1 evening $515
Disney on Ice 1 evening $105
Barnum & Bailey 1 evening $110 – 135
Rod Stewart 1 evening $195 – 715
Fleetwood Mac 1 evening $295 – 520
PS: I think I'll watch the Olympics opening and closing ceremonies on the tele - save myself a cool $4000 plus air fares and hotels.