Having done the math for all the previous mentioned factors, in my case it equates to twice the cost of the filament used just to produce the item, this includes hydro, cost averaging of footprint, etc. double that to get a wholesale price/friend price for your time and your machine's time, includes depreciation/wear and tear. Double it again to get a retail price. Comes out about the same as buying off the shelf, but with pride of makership... and you can make more than one. I did a spreadsheet that works along this line of thinking to figure it all out and whether this was doable as a business, for me it is not at this moment in my life. Cost does not include, packaging or time, effort and materials put into the rest of the mailing process, let alone marketing, advertising, building and maintaining a webpage, etc.