I think just having snow tires only in the front will still be better than NO snow tires at all. At least you have a lower chance in being stuck in snow.
On my Spec-V last winter I had snow tires only on the front and it worked great. It's a cheap way to get by and only get 2 tires. We had a lot of snow last year and I got around very well. The tires are for sale too.