Don,
If all you want is an upgrade for Excel, there are numerous choices up for auction on Ebay right now. I do not know what version of Excel you are currently using but if you want to upgrade to Excel '97, here are a few links to check out.

Excel '97 Upgrades:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=127258401
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=129542369

If you would like to upgrade to Excel 2000, follow this link:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=130419923

To see a listing of all Excel items up for auction on Ebay at any given time, here is a link (this is a long link but that is what happens when you do a search):
http://search.ebay.com/cgi-bin/texis/ebay/results.html?query=excel&CategoryID=&category1=181&maxRecordsReturned=300&maxRecordsPerPage=100&SortProperty=MetaEndSort

Hopefully this will help,
Luke