MI, I think what American Girl said is probably the key. I think people can allow themselves a bit of a reward system when they are making an effort to change, but obviously that is not carte blanche and it wouldn't be good for everyone. A common aftermath to quitting alcohol is an interest in sweets and food in general. I can remember having to tell people for years (the drinking years) I was not a sweets person but rather a salt and spice person, and would refuse sweets. Well, that interest in sweets reallly took off and I still have more ice cream than my better self would agree with, more than a year later. Caffeine too, and I think it has depressing effects.
I think it's easier said than done, but looking at what is worth appreciating, being grateful for, is a good idea when it comes to addictive thinking.
Shopping is not one of my temptations and I guess I am typically male when it comes to that, so I don't share the experience at needing to avoid it. But I can see it as a valid variation in the addiction wheel. I haven't checked lately, but there might be good literature out there on how to deal with your shopping issues. Or you could try to take the approach you use for drinking addiction and apply that to shopping.