Just bought these which are currently on offer, almost within your budget. Not the lightest but strong with a long warranty.
https://www.huntbikewheels.com/products/hunt-e_all-mountain-29-wheelset
Edit: Shimano Microspline
Wife and I have Reverse Components chain guides on our Rails and when it's super muddy we just flip them up. Also flip them when want to move the chain off the chainring.
https://reverse-components.com/en/products/flip-guide-e-chainguide-bosch-gen-4
I only have a chain guard as insurance against the day that the chain might jump and break miles from anywhere. Pushing a broken eMTB cross country isn't my bag.
Have got away with destroying a rear wheel and a derailleur in 2 years/3,000 miles without having to walk home. Result.
New 12 speed Shimano derailleur, old one lasted 2,969 miles. Clutch not working properly, too much play, basically worn out. Gotta love West Sussex mud mixed with chalk dust, a lethal combination.
Instead of Maxxgrip try Maxxterra, it's easy to tear the shit out of Maxxgrip rears. I have Assegai Maxxgrip DD on the front and after they get too worn move them to the rear which really does tear the shit out of them. I'm a 168 lb old bloke on a 56 lb Trek Rail btw