Hi
I had the angelcare monitor when my first baby was born in 2004 and I can definatley recomend it. It did go off a couple of times as he got bigger and wriggled around - and gave us a heart attack every time!! I can definatley say it is worth every penny and will be getting a new one this time around (due to have a section with my second baby 26/09!!). The new model looks even better this time with a night light and room temp on the unit.
Have you been on the angelcare website direct? I have looked all over the web and it is definatley the cheapest route at £74 + free delivery.
Believe me it is worth its weight in gold knowing that you can go to sleep being assured if (god forbid) anything did happen you would be alerted within 20 seconds. We need all the sleep we can get in the 1st few months!
I used ours until my 4 year old was about 2!! A bit over the top I know, but it didnt hurt anything and definatley kept me from worrying.
You can get the tommee one from Argos or Mothercare so you can go on their sites and have a look, i think it is a bit more expensive at about £99 and doesnt seem to have as many features - god u would think i work for them!!!
Julie x