Hi
Yep I think your butt pricing is a bit out of sync. You should be able to get Pork shoulder for less than £3.00 per kilo, I know I do, even ASDA is only £2.97KG. Bookers do 10KG boxes for £25 or £26.00
4 Kilos of meat with 25% loss = 3KG. Sarnie with 200gms meat each = 15 x £6.00 = £90 less price of butt @ £12.00 = £78.00
Now take away the price of the buns, slaw, etc etc etc. and I think you would have at least £50 profit so 150 peeps £500 in the bag in principle. One cost to watch for is any pitch/site fees as they can be a kick in the nuts!!!
But as Mr Swine states the money is made at the bigger events, but Its the initial outlay of decent equipment that hampers most and to cater for the large events it isn't cheap!!!
Also need a level 2 and or 3 C & G hygiene cert!!!