The teams in the Greek League are spending more money now than they were before the Greek economic crisis. That and Covid caused big budget cuts, but those days are over. The clubs are spending more now. Especially since the league instituted rules for minimum budgets and for paying players.
And they also instituted new financial rules for being able to register for the league, which means each club has to meet a whole bunch of financial demands before they can even register to the league.
Plus, the government's sports authority decided that the clubs need their own arenas, and the revenues from them, while not having to pay fees for them. And the clubs are getting more TV revenue now, since they started a league wide revenue system that the clubs split.
AEK
PAOK
Aris
Panathinaikos
Peristeri
Panionios
Kolossos
Kardista
Apollon
Lavrio
Maroussi
all get revenues from their arenas now, without having to pay fees to use them. Olympiacos is also going to be given control of their arena soon. And the arenas are being expanded and remodeled as well. Like Olympiacos' arena is going from 11,700 capacity to 15,000 capacity. Panathinaikos is also expanding and remodeling their arena. Peristeri, Panionios, Kolossos, and Promitheas are getting new arenas, and/or have plans to do so. Karditsa and AEK already got different arenas. Aris has plans to expand their arena.
The clubs are making more money and spending more. Olympiacos offered Sasha Vezenkov more money than the Kings paid him. Now they are trying to sign Niko Mirotic. Panathinaikos already signed two of the most expensive EuroLeague free agents (Matias Lessort / Luca Vildoza) and are said to be offering some of the biggest contracts in Europe right now.
Even a club like Peristeri has been signing well known players in Europe in the last year (Leo Kaselakis, Dimitris Agravanis, Marcus Denmon, Miro Bilan, Sylvain Francisco) - players that are said to be in the €300K euros net to €600K euros net salary range in Europe. Olympiacos and Panathinaikos have their budgets actually higher now than they did before the Greek economic crisis.
While Peristeri, AEK, PAOK, Aris, Promitheas, Panionios, and Kolossos all supposedly have total budgets (includes the taxes, so not just the net salaries) that are somewhere in the €3 million euros to €5 million euros range, and all of them except Kolossos and Panionios are playing in the secondary European-wide leagues (BCL / EuroCup). Kolossos and Panionios have plans to do so also.
So at the current time, that's two clubs in the top level European league, which is EuroLeague (Olympiacos & Panathinaikos), and five clubs in the secondary European level FIBA BCL and EuroCup (Peristeri, AEK, PAOK, Aris, Promitheas). So 7 clubs in total that are playing in one of the major European leagues. And only one that is playing in EuroCup (Aris), that these days has probably fallen to third, in terms of the level of competition, as the other 6 are all in either EuroLeague or FIBA BCL, which are probably the top two leagues now in terms of level.