I'm not sure how well received Project Farm is here (I personally really enjoy his videos), but in his test, the Crescent brand adjustable wrenches out performed all the other wrenches under $20.
*edit
Nevermind, I didn't realize the cheaper M18 oscillating multi-tool had a brushed motor like the Makita. I just went ahead and snagged a Dewalt brushless + battery and a converter for Makita batteries.