It already makes around 5-6 usd per day.
The fee is 0,05 BTC/130 USD.
It supposedly gives 8-9 USD more per day per card on that specific solo spreadcoin mining.
For a single card it means: Mine 2 weeks for the premium.
For a 3 card setup: Mine 4-5 days for the premium.
We know nothing is guarented in crypto and it is good to get when you are able to get but 130USD sounds high.
The current spreadcoin network is around 3000 AMD rx 580 cards mining with the opensource miner. If someone add 3000 cards and the price stays the same, the profit goes down to $7.5 a day. So then you can switch to nexus or cryptonite sp-mod to keep the $15 a day.
These coins are not so small, cannot be mined on multipools or nicehash so you don't need to share the profit with the newbies.
NEXUS MCAP $58 MUSD (58th biggest coin in the world)
Spreadcoin MCAP 12 MUSD
Cryptonite MCAP 10.2 MUSD