How low will you go to land a job?

I have had clients tell me that my prices are higher than others, but on the same token the other companies don't do what we do to seal up a house. They want mice gone but don't want to pay $800 to seal the structural issues I point out to them. Another company would quote them $450 just to lay down some traps and walk away. I don't like to do that because the problem doesn't go away long term, it just calms it down for a few months and I feel that can lead to negative reviews about my service. If someone says $800 is too much, I can take $50-75 off sometimes to make a deal, but most times I stand firm because I know the work involved. I would rather walk away at that point.

Do you have a set percentage or amount that you will lower your proposal to land a job?