A bit high? I think that's a pretty damn good price, considering it comes with software and a 22" monitor.
Go for it
As for building it yourself... It's not hard at all, but can be a pain. Takes about a few hours to assemble (correctly) and then you have to install Windows + drivers and then all of the applications you need.
But one recommendation I have if buying a pre-built PC is to format the sucker before you even log into the machine.
Then install Windows yourself on the newly formatted hard drive. Dell and companies a like pre-load tons of useless software that slows down the computer.