Bob, I'd take the seat and lid with you to the big box store cuz you'll need to match hinges locations if you want the new seat to fit the bowl But first...I'd give Raritan a call. Every now and then equipment mfrs--not just toilets--get a bad batch of something, or they find out the hard way that they spec'd a material that failed too quickly. Not saying that is the case with your Elegance seat, but if yours isn't the first seat that's broken, Raritan may replace it even though the toilet is out of warranty. You have nothing to lose by reporting it to 'em. 800-352-5630 Talk to Jerry at extension 236 and tell him I suggested you call.
Btw, Scott...Bemis supplies seats to just about every US toilet mfr. Not sure about the seats, but I replaced 3 in my house about a year ago and don't recall seeing that brand at Lowe's. They did have Kohler round seats for a very reasonable price, though.
--Peggie