PCB is completely different industry, sorry I can help a lot there..
If your case is plastic.. You will need to find an "Injection Mold" company..
Warning, here in the states it costs $5,000-30,000 USD for prototype runs in injection mold. But that is because the molds use to make the parts are -very- expensive.
Alternative would be to get your parts made in 3d resin (rapid prototyping) until you have a product your happy with but this can still cost you $100's per prototype. Then you work with a Molding company to get mass production quotes. Injection Molded parts have a hefty setup charge for making the mold but once its paid for its much cheaper to get re-orders done. But you always need to order large quantity to keep your costs down.. something that costs as little as $0.20 per part could cost as much as $20.00 per part in a small order quantity.
Alternatively you have
Office - Laser Cut - This is something your seeing a-lot of now days when you see the acrylic and wood cases
Commercial - Laser Cut / Water Jet Cut - This is something that is very expensive as these machines are significantly larger than your standard Laser "Printer/Cutter" these machines take up whole rooms (usually housed in open warehouses for mass productions)
CNC Machined - This is an approach I myself am using for my design, this is a timely and expensive route but can produce some amazing parts.
Sheetmetal Punched - Not sure how common this is in your area but it is generally the cheapest route for producing a sheetmetal type part (think of your computer tower) These machines very in size from 15-200TON+
Sheetmetal Stamped - This is less common than Punched in most parts of the world as the machines are much larger than the Punch machines which are already very large. Setup charges are very very expensive much like Injection Molded parts but best route when producing 100,000's to 1,000,000's of parts cheaply.
All of these are expensive in small order quantity.. Making something to sell you always have to think large volume's 100's - 10,000's of parts per order to be able to sell your product at a reasonable profit margin and price range.