Swedrami: Depends on which definition of DRM-free you're going with of course, but if a client is still mandatory to download, install and especially maintain/update/patch the game in question... well, it's not exactly DRM-free then, is it?
The Epic client is needed only for downloading the game. ("Updating" in this context means the same as downloading, after all with most GOG games you have to re-download the whole game installer in order to "update" it.).
Yes it installs the game at the same time when you download it, but if you zip that install directory and copy it to another PC and uncompress it there, no re-installation is needed. The uncompression of the zip archive is the "installation" (and then possibly the game checks some dependencies when you run it the first time, not sure...).
If you consider it to have DRM because you have to use a "client" and log into the account in order to download the game from the store, in that case all GOG games have DRM too. You can't download your GOG games without logging into your GOG account with a client.
(Fun fact: a web browser is a client, in the server-client model. It is not a server, it is a client.)
Having said that, the handy GOG installers/uninstallers, and the fact that GOG
officially supports the game as a DRM-free product, may be good enough reasons to buy the game from GOG instead. At least they are for me.
If you have some issue with an Epic or Steam game when trying to run it without the client or without internet, don't expect their support to care. Like the recent Deus Ex Mankind Divided DLC issue that GOG fixed, Steam nor Epic wouldn't have fixed it because they never promised the game would be DRM-free. There have also been cases where DRM has been added later to a game on the other services.
arrua: What I mean is, why the price difference depending on where the buyer lives? If distribution costs were something to take into account, for example, I would understand some price differences. But these products are the same for everybody. I don´t get it.
Have you never heard of regional pricing before?
The reason they do it, also for digital products, is to maximize income. They figure that in "richer"(?) countries people are more willing to pay more for their entertainment, than in poor Russia or Argentina. If they kept the same higher price everywhere, then people in Russia and Argentina would just pirate (or at least not buy) the product.
Whether that is right or wrong, that's a debate that the humankind have had for millions of years. When a caveman was selling a stick for one rock to someone and for two rocks to another, it might sometimes start wars where sticks and stones were flying.
The pricing has nothing to do with production or delivery costs, anymore than the housing market prices would be dictated by how much it originally cost to build some house. No, the houses and apartments are sold at the highest price that people in the area are willing to pay. Right or wrong? Neither. Or both.