So far in 2020, we've been averaging about one per month (and if you go back to the initial release in December, we've actually had 13 individual drops in three months, making the average closer to four drops per month since the series was announced), although the average is somewhat complicated by how you count themes that come with multiple drops, like the original Theros Gods during Worlds in February (technically, the Gods were five individual but related drops, although there is an argument for counting them as one big drop since buying all of the drops together was an option)
Other stuff is secondary
Regional Price Differences Magic card prices can vary across the UK, Europe, the US, and Japan
For other news, an adidas Crazy 1 Regal Purple colorway has been revealed.
Shops and private lots: slower, sometimes cheaper Local shops and private collectors wont always beat Cardmarket on sticker price, but they often beat it on package value