This is a question best addressed by a competent local real estate professional. One that is willing to dig in and explore specifics. A price range of between $136,000 and $150,000 doesn't reflect the specifics of the subject property and current market activity. A closer look at overall condition, size, location, upgrades/updates, etc. should provide you with the information you require to make an accurate and defendable offer.
Simply stated, you need to place the seller in the position of defending their price point. Once you have successfully proven that your numbers are an accurate reflection of the local market....you'll find you have their attention.... If not, it may be time to begin exploring other options.