Jeff
I have never come across this type of external blind so am not quite sure what they are but I wouldn't clean them anyway, the problem will be that they may not have been touched for years and when you clean them they will possibly tear, which of course will be your fault!
If you do take this job on I would prob use plain water and a semi soft deck scrubber, don't blast them with a pressure washer.
As for pricing again a diffficult question, think about how long it will take you and the risk factor and produce your quote based on hourly rate plus equipment.
Fox