[Mrkrabz]

Does anyone know the Avarage usage of a samp server?

Full and not full or Per player?

Including RAM and CPU.

[Streetplaya]

Really depends on what script they use, whether it's efficient or not.

[iLinx]

ram : 25-300(this wont happen unless the person who owns the script made something really intense or is just a retard and spammed useless variables)
cpu : depending on variables, if / switch statements, loops, and plugins