Radiant floor heat? Yay or nay?

Upon recently meeting with a local contractor, he was estimating that it was in excess of $10/sq ft for radiant floor heat.  Now my ex put it in his garage, and I KNOW he didn't spend any where NEAR that!  And his garage was massive, with 12' walls.  the tubing is cheap, there is an inexpensive grid system that you can snap the tubes in to place, its a simple water heater (small recirculating one) and that;s pretty much it.  I would say the contractors estimate was nearly double what it should be.  And a well designed system does not have to be everywhere either.
I did find this site that had great info:

WITHIN JOISTED FLOOR HEATING SYSTEMS
(including tubing, heat emission plates and fittings)
(Typical labor allotment/joisted floors 12-16 hours per 1000 sq. ft.)

Using 7/8″ PEX Tubing

• Typical floor $0.85 per square ft floor area
• Carpeted / high heat loss areas $1.00 per square ft floor area

Using 1/2″ PEX Tubing

• Typical floor $1.25 per square ft floor area
• Carpeted / high heat loss areas $1.50 per square ft floor area

WITHIN “SLAB” FLOORS (on grade, suspended or lightweight) 
includes tubing, typical manifolds, and tying materials
(Typical labor allotment/slab floors 8 hours per 1000 sq. ft.)

Using 7/8″ PEX Tubing

• $0.70 per sq ft floor area

Using 1/2″ PEX Tubing

• $0.80 per sq ft floor area

LARGE COMMERCIAL PROJECTS
(Typical labor allotment 4 hours per 1000 sq. ft.)

• $0.50per sq ft floor area

COST FOR RADIANT HEATING ZONES

FOR “CLOSED SYTEMS” (using cast iron pumps). 
(includes thermostat, relay control, pump and other mechanicals)
(Typical labor allotment 8-16 hours for one (1) zone
3 additional hours per additional zone)

Within Slabs

• $550-700 for one zone
• $1100-1250 for two zones
• $300-400 for each added zone after two add

Within Joisted Floors

• $550-700 for one zone
• $1100-1250 for two zones
• $300-400 for each added zone after two add

FOR “OPEN SYSTEMS”(using stainless pumps).
(includes thermostat, relay control, pump, and other mechanicals)
(Typical labor allotment 8-16 hours for one (1) zone
3 additional hours per additional zone)

Within Slabs

• $450-600 for one zone
• $1100-1250 for two zones
• $300-400 for each added zone after two add

Within Joisted Floors

• $450-600 for one zone
• $1100-1250 for two zones
• $300-400 for each added zone after two add