A4s on button 3-handed

[Toopskees]

Late in a home game STT. Originally 10-handed, down to final 3. Top 2 places pay. I am short stack with T5000. The other two each have around T8500. Blinds are 300-600 but are going up to 400-800 next hand. The SB was an ABC player, but the BB was loosey goosey and had made some horrendously loose calls several times already. The only reason he was still around was by catching miracle cards earlier in the tourney. I am on the button and get A [img]/images/graemlins/diamond.gif[/img]4 [img]/images/graemlins/diamond.gif[/img]. What is the correct thought process and recommended play in this situation?