I live in North Plymouth,and while there have been a few problems in certain areas let me reassure you that it's limited to a few streets. I have been here for 25yrs and I love it,I can walk to the waterfront from my home,the butcher,and the post office not to mention a host of stores and take out food establishments. Forest ave,and Forest ave extension, along with Spooner,and Savery lane are area's to avoid.
If you drive down Court St towards the waterfront you will find homes from $300k to $800k it's a mix of different homes and neighborhoods. I would recommend coming to the area and driving around,but I think you'll like what you see. Do yourself a favor and go down the side streets off of Court St. I think you will be pleasantly surprised,not to mention North Plymouth has 2 elementary schools which are also great. Cherry st is not such a great st.,Nicks Rd. is a mix,and Standish is safe if you stay towards the Cold Springs elementary school area.