Trivia: at the same time, MS also extended NT4 Workstation and Win2000 SP2 support by a year to June 30, 2004.
It'd be still be better than running IE on XP that is one of the most common attack vectors involving XP.
On AV vendors, here is McAfee's plan as an example:
And BTW, I think there is also a minimum yearly price required for a custom support agreement for XP (I think it is ~$500k for first year).
"which will be required for those seeking help with bugs and security issues for Windows XP past the April 2013 cutoff date. "
I think the $200 per PC is for the first year, after that it increases. BTW, I wonder what is the price for Office 2003 custom support.