Power supplies are often one of the most overlooked components of a custom PC build. With a bit of research, however, you can typically get a solid performer with a decent efficiency rating, all of the necessary cables you'll need and plenty of juice to spare for less $100.
Even if you have some serious high-end hardware to power, you can probably do so for under $200.
In the rare event that you simply have a wad of cash burning a hole in your pocket, you may want to entertain the idea of picking up the Cooler Master MasterWatt Maker MIJ (Made in Japan) 1200-watt power supply.
The cost? North of $1,000.
TechPowerUp managed to get some info regarding the unit on display at CES. According to the site, the 1200-watt PSU carries an 80 Plus Titanium rating (> 94 percent efficiency although Cooler Master claims the unit is > 95 percent efficient) and is built exclusively with Murata components.
Cooler Master says it took three years and 40 engineers to create it. It's no surprise, then, that Cooler Master calls it the best power supply they've ever made.
Only a few thousand of these limited edition units are being produced, likely a wise move as I can't imagine there are many people lining up to drop more than a grand on a power supply but I digress.