Your need to come up with your OWN avg price per SQ w/e and come up with a quote. Prices vary across the states, and if you are questioning this bid it tells me you didn't estimate it properly. Once you come up with what your price is per measurement down to a T you can be much more comfortable with an estimate, knowing whether you get the bid or not you gave your best estimate.
They don't want you to edge or blow? That is odd if they only request mow + weed eat services.