It claims they cost less than other Dell PC ranges, while having very similar specifications.
The Vostro 200 describes the Midi tower case in which the PC is built, rather than a specific configuration.
As is normal with Dell machines, you pick the options you want on the company's website and get a PC built to your own requirements.
You can read the rest of the review about the Dell Vostro 200 on TrustedReviews here.
Alternatively, you can purchase a cheap Dell Vostro 200 with a dual core processor for as low as £109 excluding VAT and delivery
Components
Intel® Pentium® Dual-Core E2180 Processor (2.00GHz,800MHz,1MB cache)
Genuine Windows Vista® Home Basic - English
Display Not Included
1024MB 667MHz Dual Channel DDR2 SDRAM [2x512]
80GB (7200rpm) Serial ATA Hard Drive with 8MB DataBurst™ cache
Integrated Intel® Graphic Media Accelerator X3100
48x CDRW/DVD Combo Drive
Dell™ Entry Quietkey USB Keyboard - UK/Irish (QWERTY)
Dell 2 Button USB Optical Mouse
Intel® Pentium® Dual-Core E2180 Processor (2.00GHz,800MHz,1MB cache)
Genuine Windows Vista® Home Basic - English
Display Not Included
1024MB 667MHz Dual Channel DDR2 SDRAM [2x512]
80GB (7200rpm) Serial ATA Hard Drive with 8MB DataBurst™ cache
Integrated Intel® Graphic Media Accelerator X3100
48x CDRW/DVD Combo Drive
Dell™ Entry Quietkey USB Keyboard - UK/Irish (QWERTY)
Dell 2 Button USB Optical Mouse