http://www.ebay.co.uk/itm/2017-New-V...EAAOSwtfhYtEDw
try one of those.
I've got an older version I bought a few years back.
Not sure what you get by paying more. At the end of the day all the filament based ones work exactly the same way.

You can pay a lot more and get one of the resin and uv light based pens. https://www.amazon.com/Future-Make-3...v+resin+3d+pen
These work quite differently but cost a lot more and the resin is also bloody expensive.

Me I'd get one of the cheap ones and see if it's actually going to be as useful as you think.