I am bidding on a 30 acre farm, I quoted her $30 an acre $900 total, that includes string trimming, edging, trimming bushes and blow. it will be done with zero turn mowers. it needs to be done once a week, so on a 4 week month the bill $3600. the question I have is do you give her a break per acre because there are 30 and its getting done weekly? What would you guys charge?