Spinergy Wheels with offroad tires chafe hands

Hi All- Just got some very expensive Spinergy wheels with Nevagal knobby tires for my 14 year. Worth it? I'm not so sure. We're trying to outfit him for camp this summer so we went all in after getting sized for them at the Abilities Expo.

Two problems I'm looking for advice on:

-Is there a cheaper way to solve the same problem? Should I just have stuck with his factory wheels and put some better tires on them? Seems like having tires to switch to for off-roading vs everyday is a good move. But, $1k+ is a lot of money for tires we only use when off-roading. (And yeah, I totally realize I should have had this conversation BEFORE buying the tires.)

-How do you deal with the knobby tires rubbing against your hands?

Thnks