$150 diagnosis fee. $50 for the repair and overhead ($5 supplies after markup, 1/3hr labor to include testing the system for leaks after the repair) $200 for

$150 diagnosis fee. $50 for the repair and overhead ($5 supplies after markup, 1/3hr labor to include testing the system for leaks after the repair) $200 for being the only people able and willing to do the repair. $300 because they know how much the only available alternative costs.