£433 for a 5x2x2 !!!! I take it that is with a cabinet and hood included.
If its just a glass tank you want then Windsor Aquatics (see the sponsors forum at the bottom of the page) are probably cheaper for a custom built tank, my 8x6x2.5 900usg was built on site for less than £1800, i think 6x2x2s cost around £200 and £50 delivery.