Anyway setting up such a service would probably consider that people are already paying £30+ a month to watch a few games a month on Sky/TNT anyway, on top of Netflix/Spotify/YouTube Premium etc.The thing with that is you can't really set a streaming service so much more expensive than others.
When you consider Spotify has almost any music you could imagine for a tenner a month, or all the content you can get from Netflix. Amazon, etc for a tenner a month, it'd be a hard sell to start charging £30 a month just for about 7 games, for most people anyway.
I reckon £15-20 a month max. Most people are already paying for a some subscription services for films and music and aren't likely to add another 40 quid a month on top of that for a few matches. They'd want a similar price to their other services.
DAZN is £19.99 a month, unless you pay for a year's subscription up front, then it works out about half of that. I could see that model working.
They are greedy bastards and I think they'd go high, early and take over Sky's space.
The sensible approach would be to be fairly cheap but attract a wide customer base, tempting people away from unreliable streams, IPTV and finding ways around geoblocks with VPN's.