It sounds like the construction of the standard cabinets are about as low level as they come. Is that $ 8400.00 above what you are already paying for cabinets, or overall cost? If that is additional cost, it seems excessive. Probably because they are being supplied by the builder and you are a bit at their mercy.
Personally, I prefer (and any installer I've ever worked with!) to use all plywood construction cabinets. Here are some other construction preferences:
Smooth close, full extension undermount slides have become pretty standard.
Full overlay looks better than standard. You don't see the frame of the cabinet around all the doors and drawers.
Definitely 3/4" shelves.
Flush (3/4") finished plywood ends on all exposed ends is an added bonus.
Reverse raised shaker style door - If you get a shaker style with a thin veneer center panel, you will get that rattling sound when you close the door. Better made shaker styles have a reverse raised center panel, which is thicker and more substantial.
I will always push for higher quality in your cabinetry. You may not be able to tell the difference from across the room, but you will when you open the doors and drawers for years to come.
A brand new cabinet should never be warped or "loose". Once they are installed and everything is adjusted properly, that should not be the case. If it is, it should be replaced by the builder. Check everything before countertops and crown moldings go in. it's a lot harder to swap things out at that point. Installer should note any issues, but that doesn't always happen.
I hope this helps a little!
Q
croen
Q