I agree with Shanna and Bill. A Comparative Market Analysis combined with more information will best answer your question.
Other factors not yet mentioned include: are you asking for any seller paid closing costs, how long is your Due Diligence period, how much earnest money and/or due diligence fee will accompany the $150k offer, etc.
The amount of negotiated points on an offer is surprising. Let me know how the offer turned out if you have already made it!
Amanda W. Hallock, awhallock.hpwagents.com