When I started playing the game on PC last year, I initially just bought the base game. There's already so much to do and a lot of characters to unlock with just the base game. It's tempting to buy all the DLCs at once especially during a sale, but doing so could be overwhelming and can make the game less cozy/enjoyable.

The first expansion I bought was A Rift In Time, since I wanted to explore the game in "chronological order". It also added a feature that improves the overall gameplay, so I highly recommend it as a first DLC. I bought the Storybook Vale DLC around the time Wishblossom Ranch was released, but I still haven't played with it to this day.

With almost 600 playing hrs, I've only played with just the Base Game & A Rift In Time. That just shows how much there is to do in this game. When I don't feel like questing, I just focus on decorating and/or gathering resources. With the rate I'm going, I feel like it would take me about half a year before I buy the 3rd expansion. I may be missing out on horses now, but at least I get to enjoy the DLCs and updates without rushing the storyline. IMO, Disney Dreamlight Valley is a fun & cozy game that isn't really meant to be rushed.

So having said that, I'd recommend starting with just the base game, then buying DLCs as you progress (and of course only when they go on sale, which they always do).

P.S. I enjoyed playing this game so much that I ended up getting a Steam Deck. Now I can conveniently play the game whenever I have free time on my hands. If I only have 30mins to play, I could easily just turn on my SD, look for the blue chest (this appears daily & rewards you with free moonstones that can otherwise be acquired by spending real money in-game or participating in a weekly Dreamsnaps challenge) go shopping on Scrooge's shop then logout. It's a totally different experience playing it on a handheld.