Cattle Grid Optimizer

I am a livestock agent. I need someone to code a macro so I can dump freight costs, prices, cattle weights, breed etc into a spreadsheet and it will generate, or optimize, the best returns for a client. It will need to be able to work out, based on freight costs, the optimal truck loads to go to which buyer. For example, there might be a buyer paying more money for cattle weighing 350-400kg but not paying as much for cattle weighing 400-450kg. What I want to generate is whether it is better to split the cattle to go two ways (once freight costs are taken into account) or whether it is better for them all to go on a big truck and go to one buyer (if the extra money is offset by the extra freight cost).