$90 may or may not be to good to be true.
At 400 you're out of my experience range. Hopefully others can chime in with what has worked for them.
I "suspect" that hub strength isn't going to be as big an issue for you as rims and spokes. Most reputable hubs will probably be "ok". As long as they're 36 hole or greater. Since your bike has 26" wheels you should have an easier time getting a durable wheel than someone your weight on a 700c wheel. Something like a 36h Shimano SLX hub mated to a durable mtb rim (others will have more up to date knowledge on what mtb rims are most durable) and laced 3cross with straight 14ga or even 13ga spokes.
Get more than 36h and you're typically talking about specialty tandem hubs and rims.
There are plenty of tandem teams out there at your weight that get decent durability from 36h wheels if properly built.
__________________
Birth Certificate, Passport, Marriage License Driver's License and Residency Permit all say I'm a Fred. I guess there's no denying it.