Your zip code has to be in the database of eligible zip codes:
http://ribbs.usps.gov/expressmailde...es/ExpressMailSundayHolidayStreetDelivery.pdf
(though, that may not be correct - the USPS site allows me to create a shipment even though mine isn't in the list; give it a try)
and the surcharge is, I believe, $12.50 in addition to the Express Mail postage which could be anywhere from $25-$50 for a 5lb package.
So you're probably talking $40-$65; possibly more.
For example, creating a shipment from Irvine, CA to Evergreen, CO for delivery on Christmas (Dec 25, Sat) to me from Glenn shows:
Expected Delivery
Sat, Dec 25
Post Office Price
$53.30
You can look up Express Mail Commitments here:
http://webapps.usps.com/expressmailcommitments/landing.jsp
You can put in Glenn's postal depot zip code (Irvine CA - 92620) and set the shipping date to 12/23/10 and enter your destination ZIP, and see what comes back.
You can also try to make a shipment from 92620 to your zip, mailing date 12/23/2010 here -
http://postcalc.usps.gov/
Select "Or select shape", Package, then choose Express Mail Sunday/Holiday Delivery.