looking at picking up a 03 aviator AWD (cheap) has a trans problem

I have been reading on these tranny's and I am noticing a common issue.

1st question
what tranny is in it?

2nd question
worst case scenario cost?

3rd question
is there a quick fix? like the valve body?

4th question
is it worth a $1000 in parts? if it comes down to it
has 220 Kms

thanks in advance