Several of the launch faceplates are clearanced at Toys R US for around $7.50 last I checked. If you have a Fred Meyers near you, they are on clearance there as well.
The faceplates sure haven't caught on. Personally, I thought it was a really cool idea... but where are all of the new designs? $19.99 is too much to pay, but I've bought all the ones I've seen under ten bucks. It is nice to swap out the look of the console once in a while.