Hmm, i don't usually do a lot of exploring / supercruising so i have not seen large wear and tear repair cost, but if i was flying an ASP with a 1.4 million credit wear and tear cost you know what i would do..... I would just sell all the modules at cost, then sell the ship for a 10% loss (~660k) and then buy it all right back again... i wouldn't even need to file an insurance claim and i could walk away with a nice shiny new ship... whoever developed this wear and tear money sink didn't really have their thinking cap on at the time to be honest. Unless the wear and tear comes in at under 10% of the basic hull cost then there is Zero reason to pay it, just sell everything then buy it back again all new and shiny.
I think a much better solution that has already been mentioned would be for wear and tear to actually effect the state of the modules you have fitted, so as you fly about your modules take little bits of damage over time and when they start getting too low you start getting those temporary malfunctions that happen when you get damaged, then you have 2 choices... you either give up a slot for an auto repairer that takes ammo or you have to do to pay repairs.. obviously an auto repairer would be the way you would have to go if you were exploring, so making ammo cost correlate to damage repaired would be one way to do it, would require some price tweaking but all in all i think its a much better way of doing it than having a totally unlinked wear and tear stat that only has an effect of reducing your resistance multiplier on your hull... letting your vessel get into a state of disrepair should have real consequences and you should run the risk of a full breakdown if you ignore the repeated signs of it.