So my cheap polyester carpet that was in my house when I bought it is shot and I'm going back with laminate flooring and Lowe's has some that I like but I don't know a lot about this flooring. I've helped people lay it so I'm not concerned with that part, but Lowe's has a 7mm and a 8mm that are .20¢ difference would be $160 for the entire floor. Is it worth the extra or????? What's the difference and the pad under it they offer .25¢ and .50¢ underlay ones thinner one thicker does it make much of a difference?