Smelly, I think this project will come down to whether the person is willing and able to do it on their own.
will require buying tools and some mechanical talent
I cannot speak to
pumpkinhed 's talent (or lack thereof), but assuming that he has a basic wrench and socket set (for more than decorative purposes), the Park Tool crank puller tool is $15, and the Park Tool bottom bracket socket is $19 (both at REI). So not an exorbitant sum.
also, it's very possible the rear hub can't take 10 speed
According to REI (see link above), the Scott Metrix 40 which
pumpkinhed has comes with a Shimano Altus 8 speed 11-32 cassette, i.e., Shimano CS-HG31, which is the same width as a Shimano 10 speed cassette, which thus should fit the existing freehub.
I have a cheapo schmeapo commuter bike, 7 speed, wanted to go to 9 , but the free hub is too short, I'd have to change it. Not worth it for what I use bike for, it has a riveted triple too. But i just it as is.
Agreed. A 7 speed bike usually has a freewheel instead of a freehub, which makes most drivetrain upgrades not worthwhile.