Running costs of Microlight or VLA/Class A versions of same aircraft virtually identical as long as both are on BMAA/LAA permit. Although I am not sure why you do not fancy amateur built aircraft (particularly since some of the modern kits are, whisper it, essentially factory built and assembled by the first owner), many LAA aircraft were factory built eg. Jodels, Aeroncas, Luscombes etc.
PS The Eurostar is a lovely little aircraft particularly the LAA version with 100hp. I used to have a share in one. It's just that the Kitfox is more interesting to fly, copes with rougher/softer fields because it is a taildragger with big main tyres and you can fold the wings and take it home with you if you want- see this video taken when I was selling a previous Kitfox:
https://youtu.be/rfPJGJeWk50
NB The phone number at the end is no longer valid.