I have two office locations, with an ancient AED at each location, and thinking they should probably both be replaced. Was wondering if anyone had suggestions for a reasonably priced but good quality model? Likely would get a refurbished unit. One suggestion that was sent my way is for a refurbished Philips Heartstart FR2 AED (M3860) for $499.99. Also, would it be reasonable to consider a semi-automatic defibrillator rather than an automatic defibrillator? I believe the difference is that a semi-automatic requires the operator to press the button to shock (but will still only shock if there is a shockable rhythm)?