I'm not sure what you mean by "a cheap Excel application." Are
you looking for a good price on Excel, or are you looking for
another, cheaper Spreadsheet program?
if the former, if you look around you can probably find a low
price on an older version of Excel (or Microsoft Office, which
contains Excel). Any version from Excel 95 on will work under
Windows XP.
If you want a competing spreadsheet program, try StarOffice or
the freeware OpenOffice. A Google search should turn up both of
them.