I use a matrix here, internal is cost +100% unless it is extemely expensive. I sell wholesale at cost + 40%. I don't sell aftermarket unless I have no choice or it's a brand X car. I sell anything not GM at cost x 2. I know the wholesale is my competitor, but they are never going away and they will just get it from the huge wholesale dealer in Tulsa, which means I make nothing, so that argument is invalid. My DP hates my internal mark up but daddy said too bad. Lol
Unlike Scott, my service dept does share in the price cutting, usually he takes the full brunt and doesn't even ask me to change prices, but he discounts the hell out of oil changes and charges me half so that is why.