Does anyone know some of the price ranges to run a homepage promo?
For such things, it's best to reach out to Spotify for Brands directly: https://spotifyforbrands.com/get-started/ :)
for now spotify Ads working only in US & CandaI think that spotify don't wants to make money from world wide
That's not true :) Spotify Ads are available in every country where Spotify is available. From where did you get the info that Ads are only available in the United States and Canada?
Spotify ad studio support team