Almost every room should be planned for 1 or 2 ethernet jacks, usually in multiple locations. In these modern times, many devices run over ethernet IP network.. VoIP phones, PoE cameras, printers, wireless access points, etc.

One thing to note, unlike traditional phone cabling (usually Cat3 rated) - in an ethernet network, all connections are "home run" (each cable from every jack is run to a central location, no daisy chaining). You'd end up with multiple PVC pipes, not a continuos run.

My naive guess is running bare PVC conduit is going to be even more expensive then cabling (purely due to the labor costs). One way to save is stick with Cat6 rated wiring, but do the finishing yourself - have the builder run the cables in standard gang boxes, you do the terminating to the RJ45 "keystone" jack, and finish with the face plate. On the other end, you'll want a patch panel.

If you want to avoid the mark-up, try supply the cable yourself or even consider Cat5e rated. Much of today's class of hardware is designed to have some level of backwards compatibility with Cat5e, even 10Gbps (see NBASE-T standard).

The question is what is the cost involved? I agree with MP, I can't imagine PVC is cheaper than just running CAT 5/6. Most likely any real labor costs are in the termination and in that case, you can just tell them to leave them unterminated in the box and you can get it done as needed in the future. I've generally found that ELECTRICIANS screw up CAT 5 terminations on a regular basis anyhow.

As you've heard from others running conduit is going to be more expensive than running the actual wiring, just because it's more labor intensive to install.

Why not run it yourself? It's an easy thing to do even without previous experience as long as you can follow simple instructions. Pick up a central location where your cable modem and switch will be located and run a cable to every location where you may want an ethernet point now or in the future: bedrooms, study, entertainment center, tvs, doorbell and surveillance cameras. The only rule is not to kink the cable or create really sharp turns, or damage by attaching it too tightly. Also if the cable is less than 2" from the edge of a stud or joist install a protection plate to prevent it from being damaged by drywall screws.

My guess is that you won't be able to run the cable yourself in a multi-lot development - the builder won't give you that flexibility. Similarly he may not let you opt for unfinished cable either. For one, it would slow down his construction schedule, and he wouldn't want to be responsible for errors you might make. Secondly, they make their money on huge markups for these type of options. If he does let you terminate yourself, it's pretty easy - I had my electrician run the bare cable, and I did all the terminations on both ends. Tons of YouTube videos out there, and really it's a matter of buying about $75 worth of tools, another couple hundred for patch panels, jacks and a cabinet, and then matching colors.

I ran Cat 5 to every room in my old house and never used it once. We survived very comfortably on wifi alone.

Builder wants $700 per drop LOL! I will get it done from someone after we close. Based on this should I get one conduit to make it easier to get this done after close? Will that even make a difference?

I feel like you and he must be talking about different things, because $700 per drop of low voltage is insane. I've heard as high as $200, but $700 is a totally different ballpark. Our house is a little smaller (3100 Sqft), and I have around 15 Cat and 8 RG6 which would be $15k?! Not to mention speaker cable and security.

I hope so. I will talk to him in a few days and will get clarification.