People already have probably seen this deal on the prime video site, for $2.99USD/mo you get prime video + a free twitch prime sub each month(4.99 value) for 6 months then $5.99USD, can end it at any time.
My trial had run out, today there is a trial offer via twitch(prime loot dropdown box) that allowed me to begin a new 6 month discount at the low price again. Might be worth checking out if you are in the same situation.
Do you still get ads on twitch ?