Is $15,500 to replace flat roof with TPO membrane a fair price?

This proposal outlines the replacement of an existing flat roof with a TPO membrane system, including insulation and specific detailing for parapet walls and penetrations. Contingency pricing for plywood replacement is also included. - Remove: Existing roof - Insulation: Install 1/2 inch insulation - Roofing System: Furnish and install 60 mil reinforced TPO roof membrane - Parapet Wall Detail: Install 1 3/8" round seam plates to the field sheet at the base of the wall; adhere a second piece of membrane to the wall, weld to the field sheet, and terminate with an aluminum bar - Pipes: Seal all penetrations with custom made TPO boots - Drainage: Create crickets where needed and raise ponding areas as necessary - Plywood Replacement (if needed): $8.00 per sq. ft. - Warranty Length: 5 years - Warranty Coverage: Protects against defects in materials or workmanship; complete warranty service provided if roof leaks during the warranty period - Warranty Exclusions: Disclaims responsibility for pre-existing conditions (structural damage, clogged drains, mold, excessive standing water); does not cover leaks caused by other trades, lightning, winds over 55 mph, hail, flood, earthquake, or other unusual phenomena - Warranty Void Conditions: Work done on roof (vents, drains, signs, railings, platforms, repairs, alterations); roof used as a promenade, walkway, work area, sprayed or flooded (unless specified in contract) - Warranty Transferability: Not transferable to any other person - Warranty Activation: Becomes effective only after Contractor has been paid in full