Upgrading MYW to Annual Pass?

[BelleNBeastie]

I have purchased an MYW package for 6 days. It is likely that we will visit again in Oct or Nov 2005. I am past my 45 days where I can make changes without a $50 charge. Is there any way I can upgrad to AP, and is it even economical?

 

[MagicKingdom05]

To purchase an AP it's $420.68 with tax.