channel.
Of course, we can look at other streaming services right now to see what they charge to get an idea of what they would offer. The fact that Disney+ is only about $7/month and the Disney+/Hulu+/ESPN+ combination is only about $15/month makes me agree with you that the prices for ESPN content would not be as high as one may think.
Also, there are a number of streaming services out there that provide ESPN content along with many other channels for around the $40-50/month range. If someone can get all the ESPN channels through Sling TV for $25/month, why on earth would they pay $35/month for them from ESPN directly?
Now, I could see eventually Disney adding a bundled package to their Disney+ streaming platform that provides live streaming of ABC/Disney/Disney Jr./Disney XD/ESPN/ESPN2/ESPNU to bring the price up to $25-30/month. However, I believe they are hesitant to do something like that right now as they are worried that providing live streaming options for ESPN will result in a hemmorhaging of fees they are currently receiving from cable and satellite subscriptions and hurt their negotiation of fees with those companies.