I bought a CyberPower CP800AVR AVR UPS System, it sucks. It worked once during a blackout but now cant kick to battery. Everytime I get a power fluctuation it just kills my computer. I need a pure sinewave line interactive UPS with AVR that can run one monitor and one gaming PC (idling or browsing the web) for 45-60 min. Price range: less than 300$