4L80E Rebuild

[jaronson]

I am considering buying a used 4L80E for $450, I have not seen the trans or know what condition it is in other than it works.

What would be a fair price to rebuild the thing? It will need to handle about 600-700hp.

Also, when buying the trans controller is there any advice someone could offer on which ones to buy and which to avoid? I am thinking of going with the Shrifter down the line, do I need to take this into consideration when buying the controller?