Just before Christmas I bought tickets for A Chorus Line - I spent £405 for my family of four to go and I have recently found out that I could have got seats nearer the front for a total of £210. I am miffed; very miffed. Here's how this happened.

I went online to www.ticketmaster.co.uk. I very rarely buy designer clothes or shoes, but I just have to have the best theatre seats and the screen showed me that there were just four of the best available seats left on offer on the day I needed - they weren't together. I had to buy two sets of two in different parts of the theatre. But A Chorus Line is one of my favourite shows from my childhood and to see it on my birthday with my children would mean so much to me. I took a deep breath and spent the £405, but even by my snobby theatre ticket standards, I thought that was a lot.

And then my daughter told me that we had a French exchange student coming on the day I'd bought my horrendously expensive tickets. I went to the Palladium to try to get another ticket, thinking I would buy a cheap one way up in the gods, and that my husband would have to go and sit up there! Imagine my surprise when I found that there were lots of £55 seats available on that day, all around the seats I already had booked. I had unwittingly bought 'premium seats', I was told - these are seats that a venue deems to give the best overall view. They charge a heck of a lot more for them - in this case almost double. I feel duped.

I contacted www.ticketmaster.co.uk who say that the prices are set by the venue and that they have a seat plan for people to use, however, I use www.ticketmaster.co.uk a lot and I didn't feel it was clear that there were seats in front for almost half the price. I contacted The Society Of London Theatre and they told me: 'There is no standard policy set by the industry and it would be up to the individual producers/theatres/ticket agencies to set these and decide which seats to allocate'. I Googled 'premium seats' and found that The Independent newspaper had written about the practice of 'premium pricing' for popular shows and said that it hid 'the true cost of booking the best seats'. But apart from this, there seems to have been little publicity about this issue.

And so my advice is this: DON'T BUY PREMIUM SEATS IF YOU CAN HELP IT. If possible contact the theatre itself to check all prices available. And never trust the words 'best available' until you know exactly what else is available. I think it will get to a point where Londoners, at least, know that premium seats are to be avoided, but at the moment I think a lot of people may still end up buying them by mistake.

In the end, I bought an extra ticket that is in front of the original ones - and that in my opinion is a better seat, for almost half the price. I am trying to console myself with the fact that the music from A Chorus Line is just wonderful - it's written by Marvin Hamlisch who wrote 'The Way We Were' and wrote for Dionne Warwick and who co-wrote "Nobody Does It Better" for "The Spy Who Loved Me", among many other things. I'm sure it'll be a great show, but I have spent far more on it than I needed to. I'm going to try to take my mind off of just how much money I've lost with some gorgeous free Marvin Hamlisch music.

See the allaboutyou guide to buying cheap theatre tickets