Cost depends pretty much entirely on how many I make, the more I make the cheaper they are, Ideally I would want to make a large batch of at least 25-30, I need more people to speak up and show me the demand before I can make large orders of materials.
Here is an outline of the process, just so you know what is involved
Small Bobbin
-Face end
-Drill 3/4" hole in center
-Turn down outside diameter
-Turn down diameter for primary
-Cut 14 grooves
-Cut to length
-Face end
-Mill grove across webs
-Drill holes in ends for wires
-Cut square hole with 3/4" broach
Large Bobbin
-Face end
-Drill large hole in center
-Cut seat for small bobbin
-Turn down outside diameter
-Cut 14 grooves
-Cut to length
-Face end
-Mill grove across webs
-Drill holes in ends for wires
Core
-Cut 3.5"x3.75" rectangles
-Punch out two 1"x3" rectangles
-Drill holes in corners
-Cut 0.375"x3.5" rectangles
-Drill holes in corners
-Repeat 75x per core
Wiring
-Mount SS wire on two spools
-Wire chokes bifilar, counting turns, 14 sections
-Feed wires through holes
-Wrap chokes with paper/insulator
-Wrap primary, counting turns
-Feed Wires thought holes
-Wire secondary, counting turns, 14 sections
-Wrap secondary with paper/insulator
Assembling
-Assemble bobbins, connect wires
-Stack core, bolt together
-Wire in diode
as you can see, breaking it into steps, there are a lot of tools to change in the machines, and getting everything set up, if I am making a large batch I can save a lot of time setting up the machines for each part of the process, also materials are cheaper in larger orders.
As for how much it costs, I'll let you guys make some guesses first, I haven't done all the math yet.