Builder said my quote is double what he usually pays

Long story short, bathroom is very nice. 5x5 shower, mud bed, 2 knee walls that join into a jacuzzi top with 2 steps up to the jacuzzi. The top of the jacuzzi surround, he wants tiled and the 2 steps leading up to it also tiled. Builder wants basically all the walls tiled from where my schluter stops in the shower on the right wall, all the way around to the far left wall of the bathroom, and up to the ceiling (8.5 ft ceilings) with 2 windows in the middle of the back wall (tiling inside the window seals also). Just the walls/shower walls in the master bath is 240 sq ft. The shower also has a 5 ft bench on one of the knee walls also. The master floor is 74 sq ft, secondary bathroom and laundry room floors combined to a total of 65 sq ft so in total, there is 139 sq ft of flooring. Then a 3 wall backsplash ( glass tile mosaics on mesh sheets). I quoted around $12,000 for labor and materials, which is little lower than usual for me, but was hoping to start a good relationship with a new builder who builds a-lot of homes. His response was “ thats more than double what I would typically pay”. Then says he typically pays $2700 for a 5x6 shower, $1500 for a 5x3 fiberglass pan shower and said he pays his guy now $450 for a backsplash and said “in my opinion $450 is a little high for a backsplash.” The reason he called me because his guy keeps flaking on him but I am started to see why now! I was mind blown at who would do this type of work for that cheap. Im just posting this to see some funny comments and see your guys opinions lol.