Hi Clairslloyd, Ive bought stuff off ebay for years and from all over the world, if there are any problems ie with not receiving goods just open a dispute and although it will take a couple of weeks they will always find in favour of the buyer.
Things to bare in mind though are:
Always check sellers feedback, if they are ripping people off you will see loads and loads of negative feedback, dont buy from sellers like this.
If buying from abroad make sure that what you are buying is suitable for use in the UK.
When buying from abroad certain goods may be subject import duty and VAT usually only applicable on goods valued at more than around £22 I believe but check on the Customs and Excise/Inland Revenue web site to be sure. If duty and VAT are due the Royal Mail or other courier service will collect the payment on delivery or collection.
Good luck