Nice. I'm all for a recycling ethos and understand tight money.
One pallet by two is probably about the size of plot (in a shared tenement border) we cultivated the last three summers. Things that did really well were: lettuce; spinach; rocket; chard. Roughly a square metre filled with bought-in nursery plants did three of us for salad leaves, plus spinach and chard for cooking all last summer. Well worth the money.
So were the "organic" slug pellets: beer traps are fun to fill ('cos there's usually surplus), but not hugely efficient. With a plot that small, I'd be inclined supplement the pellets with some direct mollusc control, using a torch and bucket (I tried to be nice and translocate the snails over the road to the neighbourhood cemetry ...).
This year, we've a new flat and a new gardening project that means we help one of our neighbours on their allotment by cultivating part of it for ourselves (we get the produce, the allotment stays in good order). We're finally getting organised with that, scaling up the previous approach, and adding a couple of space-hungrier crops.
There's a tame fox ...
EDIT: 8 x 4 cells in the photograph, but 7 x 4 in the plan?