As a STH, my only issue will be if the quality isn't there for the numbers accessing it. If I'm paying near £30 and can't get a brilliant picture because a few thousand folk are paying £10 to tune in, that would be galling. I don't know if there's a technical capacity for different servers or web pages for STH's and PPV'ers.
In isolation though, that's a very good price point to encourage people to watch. Hopefully all the would be pirates support the club and pay this to watch each week, even if it's 'only' the likes of St Mirren rather than find other ways.