I have experience doing this sort of thing as an investor and first of all I would need to see the last 2 years accounts.If you were sourcing the stock yourself,I would have to see the vehicle purchase invoices.I don’t think you can have set figures per vehicle,what we have done is base it on the quality of the deal.So if a deal goes wrong,duff swapper,big warranty claim,huge prep bill and there is no profit,the investor gets e.g.£50.However with good deals attracting resaleable swappers,prime finance and a very good profit margin then the investor should be able to earn up to £400.( but they are not many of them).So with a straight £1000 mark up less your vat less prep and delivery costs etc as you will net little so I would suggest £100- £125.Alternatively,If you are sending the investor to auctions to buy the stock on you behalf,you will have to pay their expenses on top.