I don't know, I travel a lot and just pay the the excess baggage charges. It's faster than freight and cheaper than a music moving company like soundmoves (their minimums are around $1000). here's what I check in: 1) cello in flight case, huge! 2) 9space rack in TV box 3) large suitcase for pedals, extras + merch 4) small suitcase for personal stuff (i'll carry this on if they let me) that's 4 items and 3 of them are heavy and oversize. the amount i'm charged varies depending on the airline and the person working the desk. if a piece is over 32kg they can refuse to take it. i had to redistribute items once to make each piece under 32. also, if you're on one of those little regional planes (puddle jumpers i call them), the CRJ , they can refuse if the plane is full. i got a flight to montreal from NYC and had to wait for an emptier flight in order for them to take the gear. of all the airlines, jetblue and alaska always seem the most accomodating. virgin is the most restrictive. if i can i try to put my personal stuff in a carry on, so i only check 3 bags. but virgin's carryon restrictions are 6kg!! and, for reference, this is what i paid under different airlines in the last two months: jetblue: $100 (always the same when they charge me. once they didn't) alaska: $50 (also always the same) virgin atlantic to the UK: $140 virgin from the UK: 180 pounds (ouch!) british airways to the UK: $140 british airways from the UK: 90 pounds united: $125 so yes, it adds up. but given what i'm checking in i think it's pretty reasonable!!