I haven't been skiing (downhill, x-country I do all the time) in years, so no idea what that sport costs here nowadays.
I do have some experience of the cost of getting into scuba as we have 4 members of the family start diving in recent years.
Training done with our local dive club.
OW course 450 eur
Mask 60 eur
Fins 60 eur
Wetsuit 280 eur
Boots 70 eur
Hood 30 eur
Gloves 30 eur
Light 100 eur
Computer 250 eur
This adds up to 1330 eur to do the course just to get started w/ diving. Regs, tanks and BCDs are supplied by the club for the duration of the course.
After the course one needs to start investing in the equipment that came from the club for the course.
BCD 400 eur (or BP/W 500+)
Regs 450 eur
SPG 100 eur
Tank 400 eur
Weights 50 eur
Compass 50 eur
Cutting device 30 eur
Miscallenous stuff (clips, smb, line, etc) 100 eur
This adds up to 1580 eur and brings the total up to 2710 eur.
With this set up, we have been doing shore dives in the lakes around here, close to home.
Then one soon realizes that diving here you really do need a drysuit. That will set you back anything between 600 eur (used) to 3000 eur (mtm new w/ undergarments)
Also, with the low visibility, a better light is good to have, add anything between 500 to 1500 eur. (the small light bought earlier works really well as back up)
So, the initial investment to start diving can easily be something to keep people from starting. Once the start up costs are over, diving is cheap. Tank fills cost 45eur/year, club membership 99eur/year and then just the cost of driving to dive sites (15min - 1hour) + fuel for club rib if it's boat dive.
Vacation diving at holiday destinations is completely different, but then one has to take into account the cost of travel.