Should I have cat6 and wireless installed in my house to be built?
I bought a pro-sumer wifi unit for about $300 on Amazon (Amplifi is the brand and came with 2 repeaters). It's low configuration and self-meshes with repeaters for total coverage. It's overkill for a lot of houses but I have an odd setup and it should cover virtually any house. I offer it here for comparison to the $200 "pro setup wifi".

1000ft of Cat6 is about $100 right now. Assuming that they use all 1000ft (which would be a LOT for a house) $700 for install in an unfinished house is steep.

If I were you, I would get a quote on having low-voltage gangs added to the house and 3/4" conduit attached (make sure they attach it to the boxes with a threaded adapter and don't just shove it into the hole) and run through the top plate into the attic. PVC conduit is stupid cheap. So let's say that you had 10 of these added. Total cost of materials (conduit, box and blank plates) would be less than $100. Add in $100 for labor (these shouldn't take much time at all in open walls) and you now have $200 in. Buy a $50 500ft spool of Cat6 and drop Ethernet into the conduit yourself. Buy a 10 pack of keystones and wall plates. Another $100 and you now have your own wired network, for a grand (estimated) total of $300 for 10 wires, not 4. Better still, what if you need coaxial cable run in? Or another set of wires in each box? The conduit supports whatever non-electrical wiring you need.