I'm sorry, but I cannot regard in-app purchases of any kind being in a game in "beta" as acceptable. The whole point of a beta test is exactly that, a test, to make sure the base mechanics work and find bugs an faults. In app purchases, DLC and deluxe editions have no place in that scenario whatsoever.
Keeping the game in "beta" for four years is an excuse to ride on to deny and delay promised features and content to string people along. It's a brilliant idea in terms of business. Only suffer the expenditure to develop half a game the milk the community for years rather than the COD or Battlefield mentality of developing a full game to only take in the money over a year or two at most.
It's much easier for to convince a player base to be tolerant and patient for a game that's in a test phase and still in development. I would be no different, but that tolerance evaporates from me the very second that game offers any kind of DLC. A game is supposed be finished before such things are even contemplated, and if the dev's claim a game is in "beta", by thier own admission, the game is not finished. Cash shops, DLC, microtransactions, special editions, there is no excuse to have any of these things in a game that isn't finished, so there's no excuse to have them in a beta. Simple as that.
What I describe as the false beta is something that isn't talked about nearly often enough in the gaming, but it is quite possibly the worst practice a game company can indulge in. It's manipulative, greedy and downright lazy. PUBG was a good example. Even when the game launched ON DISK for consoles they were still claiming it to test as an excuse for the outdated graphics and lack of full game features. The crown jewel of false tests has to be the aforementioned Star Citizen though. A "game" that's been in alpha, not even beta, for nearly a decade but still managed to take it over $300 million and counting from it's fans with pay-to-win DLC packs, some as expensive as a brand new 5-Series BMW. Escape from Tarkov may not be as extreme, but the similarities are undeniable. A "beta" that lasts as long four months would be suspect, never mind four years. I hate to bring it to you, but that game is never coming out as a complete game. If I were you, I'd jump ship before it sinks. But at the very least, please do not spend one penny more on it.