Yup, sine wave UPSes here are priced ridiculously. If they weren't I would have bought one a long time ago. As is, I haven't ruled out getting a UPS, since I'm almost done building my rig (only a gaming mouse is missing) but my interest is admittedly not very strong. If I'm gonna buy one, I'll just get a stepped wave UPS knowing that the chance of issues with the PSU (a Seasonic MII12 EVO 750W) is low. My lack of interest is mainly because power interruptions/fluctuations in my area in Q.C. are rare. They only occur predictably during times when there are strong thunderstorms, in which case it's advisable to shut down the PC rather than continue using it (a temptation, especially when one has a UPS) because of the chance of lightning strikes.
I've been also wanting to buy a UPS for a long time, but I got turned off by the risk of incompatibility with active PFC PSU's.
The cheapest APC UPS with true sine wave output I have seen is the Smart-UPS SMT750i which costs around Php 20K but refurbished units may be cheaper. Either way it is still too expensive for my needs. Factor in the cost of replacing batteries every 4-5 years and the cost greatly outweighs the benefits in my case.
So what I do instead is just set the PC to not power back on when there is a power outage. Setting this in the BIOS and getting a servo AVR with power on delay mechanism helps in minimizing the risk of damage due to the sudden power surge after a brownout. I just wait for the power to be stable before turning the PC back on. The downside though is you lose any unsaved data if you were working on something.
That's one advantage notebooks have over desktop PC's... built-in UPS hehe :-)
got my replacement psu, bnew sealed