I imagine its (partially) expensive, because they had to negotiate a custom agreement with the existing international rights holder (not sure who that is). No other club is doing this in the Championship so I guess they could charge whatever they liked to AVFC to test the waters.
Also I imagine the company providing the streaming infrastructure charged a high price also.
We (me personally also) asked Tony for this, and he got it done, so I will happily pay above market rates for it without any complaints.