per sq ft costs
This just leaves the contractor. Make sure you check them out. You can't base your decision completely on price; and, conversely, you do not want to pay too much for the job. The secret is to find a good combination of price and quality. (Not at all an easy task)
I do not know where in rural PA you are; but, if it is close to Delware I can refer you to a good contractor.
I have built from 57/ft up to 380/ft, according o what is included. I don't bid but these are actuall costs derived from expenses. Bidding is a gimmick with ways around set prices. When I used to bid, I found that I lost the war to builders who wrote contracts to deliberately exclude items or to have "allowances" that were unrealistically low. Then the change order express got on the tracks after construction was begun and the final costs wwere higher than what I had bid to include in the first place.
What you need to do is seek out a repuatable builder and work with him to negotiate a successful completion. That way you are working together.
It is only real estate agents and insurance people after the fact who deal in terms of Sq ft pricing.
But if you do want a firm price, you need a firm set of plans and a commitment that his is what you are going to build. It takes me a week to come up with an accurate estimate and I won't do it fro free.
The range you have now is as good as you can expect without firm committments.