Metroboards - priced around or under boosted price. Built like tanks. Not as sleek looking.
Meepo - ~350 shipped, as fast as boosted. Not as much torque as boosted but at least one boosted owner on r/electric skateboarding has commented that it is surprisingly capable of climbing hills. Con - not much info about reliability
Pulse echo- another new seller with hub motors - uses high quality motor controllers ~700 bucks
Raptor 2 - priced under boosted for now I think. Beastly hub motors (about 30 mph).
The space is getting really competitive so there are many more great options. R/electricskateboarding is ok for suggestions but the real knowledgeable people hang out at electricskateboard.builders
The $600 one might be underpowered depending on your use case but hard to beat the Amazon return policy if you don't like it.