WOW! I really think you are missing something. You are essentially going to mow 920 (46*20) acres for 9600?!? I am going to go out on a limb here and say without a doubt you have no idea what your costs are. If that price is really what it has been going for in the past, then that is why it is up for bid again. I looked at your last few posts and I can see you are new the business ownership side of the industry.
You need to start small and work your way up. There is no way you can do that by yourself. You WILL loose money at 9,600. Let me put in perspective for you. About the cheapest you will find rough cut brush hogging is 40/acre. If that property was to be brush hogged it would go for 36,800 for the year. You are going to finish mow, go between properties (fuel and time) trim, blow off and edge every other week for less than a quarter of that. How did you come up with your number? Seriously. I dont want to just bash you completely (only a little). I would like to help you but i need to know what you have done so far to calculate that price. If you just saw it was done for a little more than that, and you think you can do better so you go cheaper, then you will be screwed very soon. I bet if you get to looking they are paying around 10K/ month