Concrete or Clay Tile Roof - Repair

Have a less than full day job to fix leaks around two skylights on a 1 story house: 1. Remove cedarlite flat concrete shingles around 2 skylights (skylights are approx. 3x5) 2. Replace/repair flashing for skylights, reseal 3. Place new rubber roof underlayment around skylights 4. Replace shingles (I have 50 spare shingles available if something breaks) For qualified and experienced roofer to do this job, I would offer $800 ($100+/hour) plus any material expensed (few pieces of flashing and underlayment). Job can be easily completed in less than a day.