Trader Joe's is cheap! However, you get what you pay for in some cases. For fresh fruits and vegetables you are better off going to Willy Street Co-op (I joined after a few weeks of going to TJ's for all my grocery needs...I'd rather pay a little bit more for fresh ingredients). Case in point: their bagged tuscan kale. Sure, it says organic, but what you get is mostly the hard-to-eat kale stems. In fact, the stems are pretty much inedible (in my opinion) unless you pickle them!
Do yourself a favor and just stock up on the cheap wine and pre-made frozen foods at TJ's. Don't bother with the cheap TJ's beer (like nametag) though unless you like brown, carbonated water...instead buy boxes and boxes of chocolate hazelnut cookies to go with the wine!
One final note: my dog really loves the organic chicken and brown rice treats. They're pretty cheap at three bucks a pop, which beats major pet stores any day. Also, the sponges they carry are pretty rad (try cutting them in half before you wet them to make them last longer!), which consequently go really well with the lemon hand soap they sell in the same aisle.