The best way to determine an offer price would be to compare a similar property that has sold recently. If the builder has sold other models in the area, those would be your best comps. However, you have to keep in mind with new construction, each will vary depending upon the types of finishes & upgrades that may have been added. If the house has been on the market for a year, it may be possible that the builder would be more negotiable on the price. However, it would depend upon their position. But as others have said you should base your offer on other sold properties. And for your initial offer, you may want to start slightly less than where you'd like to end up to leave room for negotiation. I work in the Bellefonte Area and if you do need more information or help, I'd be happy to provide additional information.