Do you know why you want an underpad? The rug is big enough that it won't move on it's own. Once you are into this size, these rugs are VERY heavy.

What is your flooring that will sit underneath the rug? Often times the type of flooring dictates the underpad (if you need underpad).

And where is the rug going to sit? Dining area, den, living room?

Thank you so much for your reply. This rug will be in an open concept living room on a hardwood floor. It's my understanding from reading different websites that rug pads extend the life of a rug. I would imagine it will make it a little more comfortable to walk on as well.

To clarify, this isn't a thin area rug. It's a heavier loop "carpet" that will be cut to the size I need.

The $180/sf for the Dixie underpad is for a high-end fibre based underpad. This is one of the few underpads (not just Dixie...but Rugpad USA also sells this format) that is allowed over top of hardwood.

If you follow the link, you can put in the size of your rug and a list of prices will pop up for each type of pad. For a 9' x 12' rug the prices range from $129 - $152. With free shipping. It isn't much but saving $40 - $65 isn't to be sneezed at.

https://www.rugpadusa.com/collections/for-hardwood-floors

If anything, it shows that your carpet supplier isn't totally off their rocker...they have simply added retail mark-up to a product they normally use.

Can't thank you enough. I feel much more confident in the purchase now. Your advice is very much appreciated.