Best place to buy all the expansion packs

I used to play this game like 10 years ago, and I noticed a ton of new expansions are out now.

Where do I get this game? I saw it on steam, but I have no desire to download an enirely separate program to do it (steam). If I were to get steam, install AOE2, and then uninstall Steam, would that let the program work?

Last time I bought a game it was on GOG and I needed no silly client software to do so, but they do not offer AOE2.

Is there somewhere to buy AOE2 where I can just download the game without needing 3rd party software for it?

thanks