1000 sq ft one story should be about $70-80. Porch depending on size and amount of wood slats is $30 and up.
$150 is a rip off for 1000 sq ft.
I used to pressure wash with my boyfriends busines. Its cheaper an way more fun to rent it and do it yourself. Do the side walks and driveway and chairs, cars, tires and whatever else while you got it.