Unsurprising as that was inevitable and Reddit needs to make money. Unless you can afford the high prices, don't build your whole business solely on someone else's API. Twitter made that clear and now so did Reddit.
Like I said before in [0]
"Either the API gets blocked for third-party clients, or you purchase a high price for it."
[0] https://news.ycombinator.com/item?id=36087219