I bought a similar oximeter about a year ago but our puppy found it yesterday morning oO They usually go around £20.
I was looking for the same one but found this "second generation" with rotating display. As a parent of an asthmatic child I found it as real helper because my son doesn't display a classic wheezy, the oximeter gives me a better idea as to when he is deteriorating and needs medical intervention. For the money the peace of mind it provides is well worth it.
To get the oximeter for the £9.95 you have to click on the Promotion Message saying "get 30% off".
To get the postage to £1.99 opt for the "One-Day Amazon Locker Pickup get it tomorrow".