zoomie, nl10 - Attacking dead money

Full Tilt, $0.05/$0.10 No Limit Hold'em Cash, Rush, 6 Players

Hero (BB): $28.50 (285 bb)
UTG: $3.82 (38.2 bb)
MP: $7.45 (74.5 bb)
CO: $17.99 (179.9 bb)
BTN: $15.06 (150.6 bb)
SB: $10 (100 bb)

Preflop: Hero is BB with K A
UTG raises to $0.25, MP folds, CO raises to $0.80, BTN calls $0.80, SB folds, Hero raises to $2.40, UTG folds, CO raises to $5, BTN calls $4.20, Hero folds

Would you do it same as i did or you would take other options? I like my decision, but im not 100% sure about my sizing...Theoretically CO should be strong once he 3bets UTG, but their sizings arent on the stronger side...
And our stack sizes complicates it a bit...