I agree with others, that swimming price is a 1-2-1, not a group lesson. Our local leisure centre is £33pm for a weekly 30 min lesson per child. 2 towns over (home counties), I know it is a bit pricier and closer to £40pm but that's still a world away from £60 per lesson! As a PP said, swimming clubs are even cheaper (as staffed by volunteers and not making a profit past what is needed to supplement the costs of the older competitive swimmers), but in my area won't take DCs until they are already able to swim at least a length in each stroke. Our swim club lessons work out at £5/hr for the youngest ones, reduces as you move up the levels, and finally drops to £2.50/hr for the Performance teens who are training 9+hrs a week.
For us, swimming was non-negotiable until competent. Different families seem to have different definitions of 'competent', but to us that is completing the basic Swim England 'Learn to Swim' scheme (ie get their level 7 badge) and earning a high-ish distance badge such as 600m. Both DCs have chosen/are choosing to carry on beyond this.
Scouting has been a huge success and very reasonably priced. They do a great range of activities, although this can be very unit-dependent. Some are much better than others! It's about £3/wk for us (that's 1.5hrs).
Gymnastics was great at preschool age as an all-rounder for fitness, strength, flexibility etc. That was £30pm for 1hr/wk.
They now do karate. This is £25pm for 1hr/wk, although getting them set up was expensive with equipment and insurance/membership. They need their gi, pads, gloves, and gumshield, and this particular club also requires specialist shoes and nunchucks.
DCs are 6 & 8 currently.