Exactly where are you getting 4kw at 4ohms new for $750?Find me 4k at 4ohm thats efficient atleast 75% for under 1000. I can get 4k at 1ohm 79% efficient at that load new for 750
I highly doubt that those APs are 79% efficient, though you did say 2 of them.2 ap3k's are $600