I received an Email offer from Adobe for an upgrade to Photoshop CS4 (standard) from Elements 5, 6, or 7 for $299.00 (US) the other month.
The offer ended Sept 15, BUT I know several people that have still gotten in on Adobe’s deals a week or so after they officially ended (with the bad economy, I think their a little more loose about this).

Certainly worth a try, registering your Elements and giving Adobe a phone call.

 

From my Email….

“to order by phone, call 800-585-0774 and mention Offer Code stepuptoPSCS4.
*Have your Adobe Photoshop Elements serial code ready for verification.”

Chuck