We often find out what the bid was after the fact from our competition and sometimes even on jobs we didn't get. We had one last week that we had bid a large willow oak that is about 15 ft from a house and 5 ft from the fence. We bid $5200 for the job. We were in the middle of the range of other bids except for one way low one. We found out from the Home Owner that the 'winning' bid was $2000. Those guys were there from 7:30 in the morning to 7 at night with a 5 man crew. They were a bit over half way done. We figured out they would have roughly 70 man hours in the job at ~$26 per man hour after dump fees and fuel. They also broke the neighbors driveway in two places, had someone get hurt to the point they apparently couldn't use their arm at the time, and dropped a large log on top of the chip box damaging it severely. Sometimes you just really don't want to 'win' the bid that bad.
As the the workman's comp, our state doesn't require it until you have 5 or more employees. There is one tree service in our area with it. They are known to be very high priced and pay their people absolutely pathetic wages. They have a terrible safety record. I know of 4 different major injury incidents. Their ground guys are $8-10. Climbers are $10-13. Their highest paid crew leader is $15. The WC rates in our area are 55 to 60% depending on who quotes it. If you pay your people decent, it prices you right out of the market. It's already bad enough around here with 90% spiking prunes and stacking brush on the curb. Sometimes you just simply have to price what the market will bear if you want to get some work regardless of what your operating expenses should be able to be. You have to figure out how to make it work with that set amount of income.