Yes you need to upgrade on both stores to make this function work. We do offer discounts but merchants need to have at least 5 stores on Awesome with us unfortunately (then you would receive 1 store on Awesome plan, free of charge).
I can send you to the link where you can redeem our 30 days trial on your new store and try out the Cross Shop Syndication for free first before you go to Awesome officially. Will that work for you?
We are currently signed up to the awesome plan. Do we need to sign up twice and pay twice to have it on both stores or can we sync both stores and pay it once?