Does that $400 budget equal final cost?
Yep, you are gonna have assume the position when looking at RTRs out there.
Read
The
Reality (small print) that some additional items may be required (battery/charger). Electronics are gonna be very mediocre. Trying to give an attractive price point to the hobbyist will/may require company to "cheap out" the components (plastic composites used more in shocks, chassis, drive line, etc., etc.).
Anyway, I'd go with a brand that has parts support. Arrma platforms would be my first choice for a RTR.
https://www.arrma-rc.com/4x4/blx/vorteks/