usually installation fee is pretty much equipment cost. if done right, the antenna will have a small enclosure attached, in which the radio is enclosed. you shouldnt have to worry about its weather resistance, its all sealed nice and purrdy and made to be in all weather conditions. $150 isnt bad, i bet that the isp is actually biting some cost on the hardware on that one. one thing is, that with an installation fee, we know that customers are definately serious about having the service, not gonna keep it a couple month and then just drop it. they know you'll REALLY want it to drop 150 to start. but then again, you could look at like directway or other satellite services' startup / equipment costs. the average install we do is broken down like this for costs..
radio = $125
POE injector = $10
enclosure = $18
pigtail = $13
antenna = $41
totals at $207.
and these are big and ugly compared to some of the better / prettier solutions that most others are using. the setup that they should use will be an all in one type box with a panel antenna in it and an enclosure in the back with the radio in it. cat5 comin out of a weather sealing connector, running into the home.
the installation itself is pretty simple, just getting the right equipment / configuration and getting into their authentication systems is the hard part. you might be able to bargain with them to get the installaation fees waved or reduced, offer to physically put up the equipment for them. i know that we take off costs if the customer does all the drilling in the building, so we arent responsible for it.
might also ask them (the isp) if you could have a micro pop there and get some kind of discount on the service, some WISPs do that, like you get $5 off of your monthly bill for each customer coming off of that micropop. its worth a shot at least... lol. but basically give them a call and see if they will work with ya, i know that alot of the times a wisp will.
good luck with it.