Hi Samuli,
Someone on here will know this car and be able to comment. It might be worth starting another thread titled, "Does anyone know this car?", that usually attracts some attention.
Looking at the ad in detail, it's currently a non-runner because the cold start is messed up. They also claim that it ran OK but needs tuning properly. Now, it has megasquirt and bike throttle bodies, which are fine, I made a car with this set up a few years back that's still flying around on track days. But, unless you're very capable you're going to need a tuner with a rolling road who's happy to work with bike throttle bodies and megasquirt, and there aren't many in the UK, let alone, I suspect, Finland.
The fact that it appears to have never run properly also makes me wonder whether the cooling has been properly sorted, for example.
If you want an engineering challenge, lots of development potential, and don't mind not actually driving it much for some time, it could be ideal. It doesn't feel that expensive. I'll be honest, that would appeal to me. But if you want to get a car that you can drive straight away and do a few long journeys, etc, it might be a bit frustrating.