I'm a video editor and I have this Mac being delivered in the next several days. Refurbished iMac 21.5-inch 2.5GHz Quad-Core Intel Core i5 - Apple Store (U.S.)

It will fit my needs just fine but I want to find out if I could build a PC that either has the same performance at a much lower price, or significantly higher performance at the same price. Basically I need suggestions on whether or not this would be worth the effort, since I would need a new monitor, keyboard, mouse and speakers if I don't get the Mac, not to mention I'd be without the 1 year included warranty. Putting it that way, it seems like no, it isn't, but I'd like to get some feedback.