I saw a buddie of mine at the county fair tonight. He was one of the judges for the battle of the bands (winner wins the spot on Sat. night to open for the headlining band). Anyways, he owns a local recording studio and asked me if I'd be willing to rent some of my amplifiers (various 70's Marshalls/Orange) to the studio. Not on a long term basis but for him to be able to advertise that these particular amps are available for rent. So my question is, what should I charge him to use one of my amps for rental? Would I be better off renting the amps to the studio on a monthly basis or a daily basis as bands/musicians request them?