I presume you already have a monitor?
Its good for the cash, I have bought a few bits and pieces off Aria over the years but when I have bought complete PCs I tend to use Novatech, to be perfectly honest Novatechs customer service is second to none.
The closest Novatech has is this click here now it has less memory and a smaller hard drive and the graphics is not so good but if something did go wrong I feel that Novatech would sort things out a lot quicker. Price is £374.82 including VAT add approx £60 for an OEM copy of XP Home and add maybe £10 - 20 for another gig of memory if you wish and there you have a similar PC for £454.82 all in. Plus monitor of course.
I must admit Arias quote is rather good and the hard drive is slightly bigger and the graphics card is better so the choice is yours really