I hope you don't get sick of reading my replies to your postings boogs

I do have some ideas for towns that might fit. I would recommend heading north along Rte 95 (from Danvers) where the area is much more rural. Towns like Topsfield, Boxford, Georgetown etc have a number of horse farms, etc. Finding a home in some of these towns for under 300K may be a stretch, but certainly not impossible.
Personally, I would recommend looking into Amesbury. It has a very nice downtown area, plenty of restaurants, etc. Absolutely beautiful old Victorian homes and tree-lined streets. Super-convenient to Rte. 495 and all the conveniences that you are looking for, BUT once you get past the downtown, there are some quite rural areas that border South Hampton, New Hampshire. Amesbury might just offer you the best of both worlds, I would think very worth your while to look into.
Since you have specifically mentioned the possibility of chickens, you'll want to check with any town that you consider to see what limitations they might have. I have friends in Merrimac (next to Amesbury) who raise Aracana, and also the large black and white speckled chickens, and they are right along the Merrimack River. I would assume that there are more restrictions than in NH, where you can let your chickens roam free. Some towns might only allow livestock in certain areas, others may have a minimum lot size, etc.
Have you looked at city-data's information on homes?
Massachusetts Bigger Cities (over 6000 residents) has a ton of good info that might be very useful.