Take it in the kindest way possible, that given your stance the last time the question was asked your messages are mixed.
You say you would not recommend gym but at the same time you go almost to troll levels challenging others. As in life, nobody is forcing you to reply.
Thw question is:
what do you recommend?
The question is not:
From 1 to 1 million, how badly would you want to discourage someone from building a gym
If you think for example medical facility is better say that, or say that non are.
The reason i am saying this is that you are sandbagging the entire conversation and as a result little voices get to be heard because they dont want to emgage in troll level thread spamming
As for the question.
Depending on arenasize i recommend tv. Gym is strong if you need players to be better faster, but in the end, the extra costs mitigate some of the benefits. Training court is good but it makes little sense to buy it if you have high turnover of players.
A for medical facility i d say it's the weakest. Unless you are a contender or you nt needs players to be as healthy as possible, saving 3 or 4 days on a 2 werk injury is not worth it if you calculate.
As for merch. I studied merch numbers for over a season foe almost 30 teams. Merch does not bring you a fixed benefit, it inturn acts like a multiplier. The smaller the base, the less impact the multiplier has.
I saw a homegrown starting nt player in div 1 w 200k win as much merch in similar conditions as a team with 3 nt players, all reserves, same nationality. No home growns. For th lvl 3 merch store is strong. For others less so.