215/55 on 17x7.5 wheels

I have 17x7.5 wheels on my OBXT and have been running the OEM recommended 225/55/17's on it in the summer. The Goodyear Ultragrips that came on the car and which I've only run in the winter are due for replacement some time this coming winter. They are 235/55/17's and other than the traction I get I don't really care for them much. I've got a line on a set of "excellent condition" Bridgestone Blizzaks, asking price $300 but they are 215/55/17. Should I just spend the extra $100+ and get the right size Nexen Wingard Sports I've had my eye on trying or, assuming they've only been run one winter, is this a good a deal I shouldn't pass up? Or are these too small regardless?