2002 SE TX

I got a killer deal on a set of 17 x 8 BBS RK rims on eBay. They were originally for a Lexus IS300, but they have the same bolt pattern as the Max, and the offset is within the range for a 2002 Maxima. When they came in, on the back of each wheel was a sticker that read: "use only BBS-approved centering rings." First of all, how important is it for the centering rings to be "approved."? Second, would a tire store chain like Discount Tire have appropriate rings? Third, how much do they cost? Thanks, this is my first set of aftermarket rims.