blisters & chain plates
Yes, some manufacturers all have boats that may or may not blister at some time, usually on a day that ends in "Y". Which is to say that some Ericson's do indeed get blisters.
If you can find a boat that has no history of blistering (osmostic blistering), it's definitely prefered over a boat that has blisters. Same for the chain plates. Bad chain plates generally indicate deck leakes, which means that not only do you need to address the chain plate repair, but also repair the rotten coring in the deck and then stop the leaking.
The purchase price is dictated by the condition of the vessel. The less you have to repair, the more it's worth. All these things can be fixed, but there is a cost for materials & the labor if you cannot do the work yourself. This can add up to several thousand dollars depending on the boat & how extensive the damage is.
One of the best investments you can make is a marine survey of the prospective vessel prior to purchase. This will give you a real good idea of the extent of the damage, if any, and you can then work out a selling price based on that information.
I hope I haven't confused the issue for you. I have owned 3 different Ericson's, done bottom repairs on all 3 to some extent, but bought them at prices reflecting the work necessary. The more work they needed, the lower the purchase price. Generally speaking, I feel that the Ericson line is a product worth repairing because the overall level of quality is quite high as compared to some other makes. I am also able to do all the work myself, so that make a big difference, also.
Good luck in your boat hunting.
Have fun & sail fast
Bud E34 "Escapade"