Look into shopping at Market Basket. It's like shopping at Costco without having to buy in bulk. They make their profit by keeping prices low enough that they sell 50x as much as other grocery stores. The one in Somerville on Somerville Ave. is very cheap (I guess I didn't really go visit the others). I got CA produce cheaper there than in CA. :P But don't ever ever go on a weekend. It's a madhouse. Best time to shop there is like 8pm at night. They close at 9pm. Not T-able, though.
You can live near a T, and use Zipcar when you need a car.
Absolutely do not own a car and live in Somerville without having an off-street parking spot. Trust me. They will ticket you up the a** and then some. Street cleaning is (or was last I knew) twice a month on each side of the street. So you could end up with 1st and 3rd Thursdays and 2nd and 4th Fridays, and unlike Cambridge, they won't come through with the guy on a bullhorn saying "Today is a street cleaning day, there is no parking on the right side." And the worst part is that the Thursday/Friday may not end up being in the same week, so it's easy to forget (and if you're REALLY unlucky, every street around you will have a DIFFERENT street sweeping schedule. Try living somewhere where your street is 1st/3rd Thursday, 2nd/4th Friday, next street over is 1st/3rd Monday, 1st/3rd Friday, and the major street is Tuesday/Thursday Midnight to 6am). Tickets are $40 or more per incident. Luckily they don't tow you. Then snow plowing days can also get you ticketed and towed. And if you happen to park, oh say, 6" into a crosswalk--like your bumper is right where it starts to slope down, they'll ticket you too. And 20 feet to curb is sometimes arbitrarily enforced and not painted on the sidewalks. I once saw some poor soul with over $300 of tickets for parking 20 feet to curb, 6" into the walkway on a small one way street where we all parked exactly the same way.
And don't get me started on guest permits.....
And do not ever be pregnant and have to go to Somerville's Traffic and Parking [Edit: I originally said DMV, but I meant T&P]. They have no mercy and no bathroom.
I will never ever ever live in Somerville again.
Well.... maybe if my life depended on it.....
Naaaaaaaaah. Not even if my life depended on it.