Indeed, LPG was a seen as being very expensive, however this was partly due to customers being trapped in long contracts with little control. However, the Competition Comission has ruled that customers are now eligible to easily switch supplier to find the right deal or service, as long as your existing contract has passed the two year mark. I'm with LPG Home Heat, who supply LPG across the North of England. They're a small company, but their service is great. I have a home care package system which was specifically tailored to my useage and needs. Their website has loads of information about the Competition Comission rulings and how to switch. If you're already an existing LPG user, you probably won't even have to change your tank either.
www.lpghomeheat.co.uk