Most violins (bodies) are actually made out of Spruce (top) with Maple used for the back and sides.
The reason Spruce is used is because it is strong along the grain but laterally flexible - the front or top of violins always has the grain going along the length instrument, enabling it to vibrate in the correct way. It's all to do with the way the body resonates and vibrates... which is very different for an electric violin.
For an electric violin it's a totally different storey - You're slapping wads of paint onto the wood of an electric violin (as opposed to thin layer of varnish on acoustic violins), using a pickup for the sound amplification (and added colouring!), not relying on just the body of the instrument, plus with most electric violin designs, there's so little wood there to vibrate/resonate, you could use just about whatever wood you wanted (within reason!) and it wouldn't make a whole lot of difference to the *ahem* "tone" of the instrument.
So with that in mind, the costs for the body/neck should be virtually nil cos you probably have enough wood lying round as leftovers from other projects to cover them that is more than adequate quality. If not, it's still not going to be much of an expense. Fingerboards need to be a hard wearing wood (on cheaper violins it's usually stained rosewood or boxwood or cheap ebony but on better quality instruments good quality ebony is used) and again won't be a noticeable expense if your making it yourself.
Pots, knobs, jack and wiring should not come to much but added with the costs for pegs ($12), tailpiece ($10+), chinrest ($6+), Bridge ($4.50) and the pup ($130) will blow your budget (example prices just from stewmac). Plus unless your carving/machining skills are good, it will probably take alot more than $100 of your time to make the neck (if you want it like the one in the piccy - with a traditional scroll/peg box)...
To be profitable, I would use high quality components, make sure the quality control is tight, use good/interesting/unique designs and aim for the mid-range (£500 ish) market. I think only mass produced stuff using machines that are already set up and marketing that's already in place can possibly compete to sell this kind of thing profitably in the budget market.
Of course, that's only my opinion based on the "making-to-sell" mindset and I am in the UK - it could be a totally different scene in the USA?