That seized caliper bolt on a 2011 Focus ate my whole Saturday

Had a 2011 Focus come in with a dragging rear caliper and I figured it was a quick swap, maybe an hour tops. The guide pin bolt was rust welded so bad that my 3/8 impact just rounded the head, and I ended up spending 2 hours just getting the torch and extractor set out. Around hour 4 I finally got the bracket off and found the piston boot torn to bits, which meant a whole new caliper instead of just pads. Back when I started in this trade you could spray some PB Blaster and things came apart, but these newer cars with all the salt up here in Buffalo turn every brake job into a fight. Total time was just under 7 hours for what should have been a 45 minute job, and the customer still thought I was padding the bill. What do you guys do when a bolt is that far gone, drill it or just cut the bracket and eat the cost?