Brad Pratt's Advice

Bottom line... over 90% of For sale by owners eventually hire a real estate agent.

I would not trust a Zillow Zestimate.  A Realtor is your best bet if you want current market value.  Zillow is known for not being accurate.

I would not even bother with a Zestimate.  They are wildly inaccurate.  Definitely call an experienced Realtor to provide you with a comparative market analysis.

As long as your Realtor structured the offer properly, you should have the time to either get the invoice showing a new roof was installed or if not then to renegotiate the sales price.  All the while your deposit money should be safe.  If you need more time to get the information you need then ask for an extension to the home inspection contingency.  If the seller refuses.... back out of the deal and get your deposit back.

Zestimates are wildly inaccurate.  Your best bet is to call a Realtor who will prepare a free, no obligation, comparative market analysis for you.  It will include comparables from at least 4 categories.  Sold's, pending's, active, and expired's. 

More than 80% of FSBO's eventually call in a professional.  National statistic.  If you decide to make that call please keep me in mind.  I would be happy to help.

I have never seen an accurate zestimate.  I did one for curiosity sake on my property and it came up with $480k.  I just sold it for $700.  You should have a Realtor do a complete free, no obligation market analysis. More than 80% of FSBO's end up hiring a Realtor anyways you might as well see what one has to offer.

If you want to research schools try Greatschools.net.

I Have been working with Leah Martin at Salem 5 home loans for 10 years.  She is by far the best in the biz.  Her number is-   781-727-5365.

Luo,If you are looking in Somerville I am happy to help you.  I have lived there since 1996.  Just contact me through zillow.  All my info is here.Brad