The buyer never worried about insulting you with their asking price. You should not worry about insulting the seller by your offer price.
Offer low, and be prepared to walk if that is what you feel it is really worth to you.
Your agent can do a market analysis and compare the home to recently sold properties in the immediate area. They can also research the subject property to see if it's been reduced, any disclosed problems, etc. Once you go over the analysis with your agent, you will know how much under the asking price you can go. Good luck!
10% under asking price is normal for the 18657 area. I would say have your agent give you comps to help determine a price to offer. Call if you wish to discuss more.
Century 21 Sherlock Homes
My website: http://www.century21paonline.com
My # 570-746-0383
Your question is the most complex question a buyer can ask! There is not short answer. That is why I have posted the link above for you. It is the answer to your question in a blog post I wrote not too long ago. I hope this helps you!