the cost of the permit (2000 dec) make no sense.
here is example:
my battle (https://splinterlands.com?p=battle&id=sl_eee787e1c42e1d85150f315a6e992ec9&ref=khunjuice) get +0.318 sps per battle at Diamond II (rate before battle 3240) with x2.15 boost from sps stake (all card at the lv with maximum possible rewards).
So at x1 boost, I will get

0.318/2.15 = 0.148 SPS per win. (round up to 3 digit)

stake boost maximum is x13.3 (according to https://support.splinterlands.com/hc/en-us/articles/17101979325972-Reward-Multipliers-from-SPS-Staking)

0.148 * 13.3 = 1.969 SPS per win. (round up to 3 digit)

a season varies between 12 and 18 days.(https://support.splinterlands.com/hc/en-us/articles/11631144908436-End-of-Season-FAQ) and we get 24 energy per day. So we get

24 * 12 = 288 energy per season.

but let be real, a lot of people that aren't will bot not spend all energy. so I will be said they play 80%

288 * (80/100) = 231 energy (round up).

So with 50% win rate.

(1.969 * 231 ) * (50 / 100 ) = 227.42 sps (round up).

with current trade value 227.42 sps = 2537.862 DEC

profit is SPS get minus permit cost
2537.862 - 2000 = 537.862 DEC

1000 DEC is around 1 USD so 537.862 is around 50 cent

we need to stake 391746 SPS (with / 2 we need 783492 SPS) to get x13.3
(https://support.splinterlands.com/hc/en-us/articles/17101979325972-Reward-Multipliers-from-SPS-Staking) to get 50 cent a season or 1 USD a month.

I pay for fun so I don't mind double sps stake need for boost, but the pay to play model is stupid thing ever. To make even, I need to play a lot and make the is become work. I lot of causal player will leave.