Hi,
I've lost my first 15 ounds with WW but found that I plateau'd as I kept eating too many carbs. I've done the first week of phase 1 (and not stuck to it 100% either) and have lost 4lbs so far- so it's kicked me out of my comfort zone.
I'm not cooking for a family but we still have a budget- I've found that concentrating on veggies, beans and seeds with some eggs, low fat meat and cheese has actually kept my shopping bill down.
As for coffee, that's one area where I've not been strictly on plan, and it doesn't seem to have affected anything. I do drink it black though.
Good Luck with whatever you decide.