Amazon is having Therm-a-Rest NeoAir XTherm MAX sleeping pad regular size for $139.00 w/FS and no tax in most of the states. Or $167.95 for large size.
This is a highly rated lightweight sleeping pad with R-Value of 5.7 and 2.5 inches of thickness. Look at the pictures and you'll see how compact it can be for backpacking. I have one and couldn't be happier with it in winter camping. This is rectangular shape if you want extra space from the mummy shape one and don't mind the 2 oz extra weight (in regular size).