Presuming that you picked a good surveyor in the first place, I would look askance at the boatyard's advice...
Local boatyards around here (PDX) make money on their regular bottom jobs, and consider them the bread and butter of their business. Do you have another local yard to consult with?
It does sound like the old paint needs to be removed down to whatever level reveals well-adhered paint. Then, any areas of blisters need to be filled and faired. Considering that this involves some ugly sanding (even with the vacume sander), I could see the price rising to around $900 or a thou.
For a $$ comparison with a high quality yard, look at this web site;
http://www.schoonercreek.com/service_yard/rates.htm
They normally do my 34 footer for around $900, and reduce it in the fall...
Your 30+ model is a very good looking Ericson. I hope that you get many years/decades of pleasure out of it!
Best,
Loren
Olson 34 #8, Portland, OR