Sometimes you don't know what is going on with your competitors, I lost out on a very large contract this month (over €60,000.00 for one clean inside and out 70 big buildings). It turned out that the company I lost it to have done it at 32,000 as a loss leader to get in the door for the overall contract cleaning contract for next year. They will lose over 10k on the contract how can I compete with that.
It does go to show that there is always someone out there who will have a reason to do it cheaper.
Put it down to experience and go on to the next one (only after drowning your sorrows very deeply) , thats my advice