Talking about SB that in my mind works similar to JR, this is not expensive if the combinations of the other skills is not so high but if you've a big man completed by high SB skill his salary is really expensive and also in this case I think we have to find the best compromise between lvl of skill and salary. I don't know how SB can improve your player but for sure in case of great player SB has a big impact in the salary and that's easy to see in the TL ;)
1990-2022 Stalinorgel - https://www.youtube.com/watch?v=pV-Xppl6h8Et