labor to install tile heater ?

Ok so I installed my electric radiant floor heat in my bathroom the other night. I took and glued the heater pad to the hardibacker and wired it up along with the temp probe. I painstakingly glued down the matt so when I poured self leveling compound it would burry it very well ( had bad results when not taking time to do this) so that it would all be burried. It took me quiet a while because the area to be covered was not perfectly square either (neo angled shower) So after a long night of installing the heater, running the wires to the box, using weather strip foam on the perimeter of the room and laying the self leveler it took me about 4 hours. I started to think, "how much should I charge a customer for this?" I was thinking an additional 300 labor is fair. Hell an electrician just to hook it up would be 100$ it was 25 square feet so If I was to include materials it would be as follows:
Floor heater 250.00
Thermostat 100.00
Self leveler 150.00
Heat sensor 25.00
Labor 300.00

Total : 825.00

Am I way out of line? Seems reasonable to me, but those of you in the trades would know better than me.