just another opinion
1. calculate your cost of equipment (in money terms including service, calibration, "licence" and maintenance costs) versus the expected service life in hours. This way you will work out an ammortization cost per hour, so you could have an estimate of your cost per hour of show. This can also be perceived as the devaluation of your kit over time of usage (4000gbp for a projector that will last for 10000 hours of usage, so 0,4 quid per hour. of course you can raise this a bit to include repairs etc )
2. figure out how much your manhour of programming the show costs. then, if you spent 10 hours preparing a show which will be displayed for 5 gigs, spread this cost evenly across all 5 gigs. If it is an one-off show, all programming time/cost should be added onto that gig
3. figure out how much your manhour of projecting costs. Include time for set-up and checking / rehearsals
4. calculate all materials you will need, buy, rent etc and figure out their cost. again, if it is a tour, spread this evenly across all gigs in that tour
5. calculate all transportation, accomodation, food etc costs
6. if you have to take time off work, add an ammount to compensate for the income loss from your normal work (in case you take leave of absence without pay)
up to this point you have not earned a signle quid yet
7. add a nice ammount to all the above costs, so this will be what you really earn from the tour-gig etc
as a general overview, there is no single best of the best costing model. a safe way to go by, is to divide the costed project into steps / phases and determine which is the limiting factor in each phase. limiting factors (or scarce resources) can be machine hours, manhours, warehouse space, raw materials etc. Every time, the scarce resource determines how each cost should be broken down and valued
hope this helps
"its called character briggs..."