You're right that I am not considering the tournament fee's at all in this data. Generally for all the tournaments I play in a season it ends up being around $12-$13 worth of DEC for both accounts.

If we multiply that by 39 seasons it comes out to $507 in tournament entry fees. Since I'm projecting (over 39 seasons) winning around $4,425 it's still well worth it but it does come out to about 11.5% of my total profit from tournaments.

Personally I am okay with the fee's because I know it also helps DEC supply and thus SPS price and I am a holder of SPS so indirectly benefit from burning my own DEC to play tournaments!

If you mean the scarred hand cup's that only use the newest set. It's hard to say if they're worth playing to you or not. They have a small portion of the total tournament reward pool allocated to them so they don't have the biggest prize pools. But they also don't require much DEC to enter either so they are low risk in that sense.

Ultimately it comes down to how you want to spend your time. If you think it's fun or just want some extra SPS I'd say go for it! Maybe you'll find you really like it and end up playing other tournaments too!