I can recommend cooking in batches. I used to be buying ready meals for work when I was first doing WW...probably spending £3-£4 a day on it. Doesn't sound much, but does add up...and when you compare the number of meals you can make yourself for the equivalent price, it doesn't bear thinking about. Made the switch to cooking myself a few months back, and haven't looked back. You get better meals and more variety, for less of the cost.
Best bet is to go to your local library & see if they have any of the WW cookbooks in stock, then knock up a few of the meals in them. Think the best meals I've done as the mousakka in one (can't remember the book, but it has a blueish cover with a pot of creme brule in the corner. lol)...made up four portions for a couple of quid, which was great.
LIDLs or ALDI are also great. I eat Quorn a lot, and they've always got bags of their mince or sausages going for £1.