To ask for $5000 and then an extra $500 per year sub fee is scaring tons of people away. This would not only drain your wallets, but you'd have to be confident enough that the business would still be around, AND that the game would constantly be updated. If the last 7 years are any indication, they didn't build this type of reputation to be able to do something like this.
If base RAZA was sold for $5500 w/ no subscriptions fees, I think deeproot would sell far more units, and they'd make the same amount of money per game anyway.
There's no way I'm buying one with a subscription.
I'd be very interested otherwise.