As you say I might be bad at diy but as a professional I am top of the tops. Looks like that there is no space for you to improve if you do not try one, try one with variable speed and you will find how many 100's of things you can do with it and the most important thing is that you get the quality and price can be the same if not lower. Few month ago I bought a third one from LIDL at £10, was the last and reduced ofcourse otherwise they usually cost around £20 or less.

This is pretty much the same item ie low end/disposable (no spares available) for £18.69
http://www.argos.co.uk/static/Product/partNumber/2463638.htm

If your budget allows screw fix sell the Bosch professional one for £34.99. Far superior quality and a great price.

It may make a difference if you're bad at DIY, otherwise it's fine. I bought the 9" version of this and it was great for cutting slabs, but needed something smaller to cut holes in a car bumper reinforcement panel so bought this. Just like it's bigger brother it's been faultless

around that price or less you can get a better one from LIDL(when on sell) and variable speed too. It does really makes the difference

no variable speed

I have this, it's lasted well, the only con I have with it is the location of the power button, would prefer one located on end of machine not top.