You can find much cheaper if you look around.
Try to find one that will offer some sort of web-based admin panel (often CPanel or some custom made one by the provider - they should at least provide some screen captures so you can have a peek).
Search for shared-hosting. you should be able to get plenty of space (over 1gig) and decent monthly bandwidth and PHP, MySQL, multiple domains and sub-domains for something that is between 10-20$ US a month.
Those services are cheap, so you might run into sporadic downtime/slow downs (most of the time you won't notice), but if it is a personal project and even a mid-sized project, it tends to perform quite ok.
Of course, better services on less populated servers are more expensive... just try to balance things.
Of course this information is based on North-American prices... I do not know the market in the UK.