Yes, it can be a challenge if comps are difficulty to come by. You (and your Realtor) have to do the best you can. Find the best comps, then adjust them based on the difference between them and the property you're interested in.
I'd also bet that if you actually took a look at some of those houses, you'd easily see why there's such a wide variation in price per square foot. (Age, lot size, condition, improvement, location, etc.)
Hope that helps.
Understand that the LISTING PRICE has one primary objective, to attract attention: It is not intended to be set in stone, and in many cases it is not even a good guideline toward the SELLING PRICE.
Some Sellers believe that by setting the LISTING PRICE high, they can always come down, and people will make an offer anyway: WRONG! Buyers will just bypass the property and look at houses that are within their price range. And six months from now, the Seller will slowly start lowering the PRICE, (this is called â€œchasing the curveâ€) and Buyers will be asking the question; â€œWhatâ€™s wrong with that house?â€ and â€œWhy has it been on the Market so long?â€
Other Sellers set the LISTING PRICE low, to attract multiple offers. (The correct strategy.) We are asked; â€œArenâ€™t you obligated to sell at this price if someone offers it?â€ The answer is probably not; for that to happen, you would first have to have only one offer, and secondly, the offer would have be exactly the same, down to the smallest detail, (please discuss this with your Realtor).
Another thought; Buyer will search for potential properties by groups; for example, $400,000 to $450,000, and $250,000 to $300,000. If your house is priced at $460,000 or $310,000, the Buyers will never see it. (something else to discuss with your Agent.)
Different Banks have different philosophies about pricing their properties: You cannot draw any conclusions without a good analysis.
Have your Realtor do a CMA, (Comparative Market Analysis) to help you determine your Offering Price. It is the surest way to determine the Market Value of the property.