You can find the exact specs of our witness server in the announcement post for @lux-witness. It's the top offering from contabo.de (50 GB RAM) and it costs about 30€ / month.

Even if 25 SP < 30€, I wouldn't call that "losing a lot". As explained again in the various posts of @lux-witness the goal was not to make money (although making money is always a nice plus) but to learn