I did some math, I love math. Using your original 40Th contact for $5200.
Maintenance cost per day = $11.20
Maintenance for one year = $4088
Best case scenario, the difficulty of BTC stays exactly where it is, you would create exactly 4 btc.
Profit at current btc value = $18112
Minus the cost of maintenance = $ 14024
Realistic scenario, difficulty increases at a normal rate, creating 3.43 Btc in one year.
Profit = $ 15601
Minus maintenance = $11513
Closer to worst case scenario, difficulty increases a bunch, giving you 3.12 BTC.
Profit = $14142
Minus maintenance = $10054
Now let’s say btc goes up to $10000 in that time, that’s potentially $30k, or $25k after maintenance costs.
But what if you bought altcoins? You could either end up doubling your money or multiplying it by 10 or 20 times. Who knows.
Edit: Where are you guys seeing this 27% pool fee? That would make a huge difference on my calculations, obviously.