"Ain't that the truth!” (3,3)
There are a few possibilities for this:
ill say
(Other definitions for indeed that I've seen before include "Without question" , "beyond doubt" , "In reality" , "Expression of interest, incredulity or contempt" , "Truthfully, really" .)
(Other definitions for ill say that I've seen before include "I totally agree!" , "Rather!" , "I couldn't agree more!" , "Absolutely!" , "You bet" .)