Sounds crazy to me but I've never put in hot water radiant. I have put in electric radiant under tiles in bathrooms and kitchens but they were dirt cheap (compared to your estimate).

Get more estimates if you are set on radiant..

You plan to install radiant in the basement floor? Will it go into the concrete or is there a subfloor?

Are you doing this for better comfort? For a lot less money you can get a very comfortable forced hot air system.

Will go into concrete if we do it. Worried about it being to cold with tile floors? Builder did suggest foam insulating below concrete but not sure if that would help much. Thanks for your input.

I have hot water radiant in my new home in northern NY, and we love it!

Don't know what it cost, because it was part of the total build, but I doubt it was as much as you said. 2" of rigid foam was put in before the basement pour, as well as outside the foundation walls. Yes, it does take a long time to heat up, but once it's warm, it stays so. The builder put in 4 zones in the basement floor; only one of which is in use because the basement is still unfinished. However, it is plenty warm. We also have 4 zones in the first (and only other) floor. We really love how quiet it is, which we would not get with forced hot air.

A good installation of modern forced air heat will not be noisy. Despite that pronouncement, if you have the money, radiant floor heat is wonderful in predominantly heating climates. Hi mass radiant heat (read in concrete), however, is not a good match for areas that you want to vary the temperature. One example would be a rec room where you might be exercising one hour and sitting down with the family with popcorn to watch a movie the next couple of hours. Another mismatch might be bedrooms for people that like to sleep cool, but want it warm when they go to bed and get up.

Furthermore, a modern build with low heat loss and a boiler closely matched to the load will probably not see significant economic benefit from deep set-backs. In fact, recovery can kill the boiler efficiency forcing it to heat the water to a non-condensing temperature. Any temporal temperature changes would be for comfort. I don't know if there is any hope of boiler manufacturers getting on the stick to inform their boilers so they can differentiate between a set-back recovery and real demand to maintain temperature so they can recover from a set back efficiently. (Note that this is a similar problem to what was faced with heat pump set backs/recovery hitting the resistance heat strips early in the days when they were first becoming popular for residential use.)

It is not clear to me why any builder would put multiple zones in a new home constructed for energy efficiency. Heat transfer from room to room is much greater than from inside to outside the building envelope. The heat output for each room should be matched to the heat loss so separate thermostats are not needed. If temperatures need to be varied from hour to hour, a bypass thermostat installed in that part of the loop is probably a better solution than a separate zone. Hydronic systems require a lot of engineering to really get them right.