No, and Yes. I have had to reduce my service rates from last year. I have found I am way on the other side of the supply demand curve. I try to be just to the right side of top but the demand dropped way down changing how much supply should cost. As the insurance commercial says "if we cant increase the value of our service we can increase the value of our price."
USM, yup they have called, and yes I have even gotten paid by them. I have had a few service companies call. So far I haven't gotten a warm and fuzzy feeling about any of them. One I have heard about was not licensed to do work in my state and now have issues. One is still calling about emergency work they called about last year. Its a crap shoot. I prefer to deal with the owner of a property and not be a sub sub sub contractor. It makes it an interesting proposition to get paid when you cant represent yourself as having done the work.
The one thing I think is best when dealing with service companies is written communication. Get a credit card up front and process the fee when done. Make clear investigative costs are separate from the service call. Get them to OK the service agreement with an addendum to allow you to collect from all parties if not paid within 30 days. This might be a deal killer but will open up the conversation on payment. I think they make a percentage on the gross. Book rates of some sort may be easier to negotiate then them telling you how much they will pay for unknown problems. If they are calling you they are calling others, if you can get an exclusivity agreement for your area if it works out. Good luck. USM has been OK to work with so far. I have only done 2 jobs for USM. Both jobs have been good for a days worth of work. They have paid within 60 days. I feel uncomfortable being a sub sub sub contractor only because it puts me at a disadvantage.