Best thing is its free !!!! The only costs are the server (retired machine with a graphics card fault), the electricity to run it (expensive !!!) and the ADSL (around £30 a month).
If you are looking for a similar setup - any decent Linux hosting will do as long as they allow you access to MySql
phpbb goes on in 15 minutes
oscommerce takes slightly longer (20 minutes) but then you've got lots of setting up to do. Oscommerce also integrates with Paypal and many other payment systems with third party addons which cost the same as a breath of fresh air