I've made it all the way to February third without buying any toys! Albeit the day has just begun, but I've got a full one so toy shopping is out of the question.
I also discussed this challenge with my girlfriend and she said 'what if we're at the swap meet and you pick something up and put it down and I buy it for you?' I told her that was perfectly acceptable and did not violate the challenge. Now we just need to work on our hand signals so she knows what I can't live without.