I think you might be confused as to what kinds of manufacturing are available, blow moulding is pretty fast and easy, you might be thinking of that, or maybe resin casts with rubber moulds, even hobbyist`s can do that, so some plastic moulding techniques are fast and easy, but the Pandora case is injection moulded, you use really high pressure to force the plastic into the moulds and leave no air bubbles, and I mean REALLY high pressure, to prevent the mould popping apart before the injection is finished they have to be clamped shut, in the industry the clamping pressure standard unit is the ton, so the mould can`t be flimsy.
so they have to create a really strong mould out of solid steel thats highly polished and will not bulge during injection, then they have to allow for "sink", when the plastic cools it shrinks a bit, if the plastic at one spot is really thick then when it cools lots of plastic=lots of shrink, so you are left with a dimple on the product or a too short support post etc, so they may have to modify the mould to prevent that (thats why sometimes you see products where the internals are made from two or three parts rather than cast in one, so now you know why they did it the "hard" way)
then you have to think about production speed, the mould has to be water cooled so that once the part is cast it can be removed from the mould as soon as possible rather than waiting a hour or so for it to harden, to do that you have to model the heat distribution in the product and then place water channels in your solid steel mould too cool it down without warping the thing being moulded, all the while remembering the immense pressure used during injection.
THEN you have to get the thing out of the mould, that means ejection pins so that when the mould unclamps and opens, the product will just pop out, rather than you having to go get a screwdriver and lever it out <_<
so a mould is a multi ton resistant, solid steel, internal pressure resisting vessel, water cooled, with sliding ejection parts, that self dismantles to allow the product to be removed, highly polished, and made slightly oversize to allow for shrinkage, you don`t make one of those in a couple of days, thats the reason why many small manufacturers and electronic kits use ready made cases, it`s cheaper and easier, the stuff you are talking about is
probably cast resin or blow moulded, neither require fancy, high precision moulds, either that or your firm pays a premium for fast tracked manufacture.
http://www.toolcraft.co.uk/index.htm
linky thing, very informative
remember, an initial order for 4000 components in an industry that makes more than that from one machine in a day will not be getting preferential treatment, they have to stop whatever the machines making, change the moulds, run off 4000, (one minute injection cycle and four cases per mould == 1000mins work == 16 hrs or two shifts on one machine) then stop the machine, change back to something more profitable (say 20,000,000 Wii controler cases) then restart the machine, they will probably fit it in where they can, plus we probably only have the one mould, most firms I work with charge for the moulds unless the contract is very big (when it in all probability gets factored in on the product price), interestingly, at least here in the UK, when you are charged for the mould (and most customers are) that means you own it, so if you want you can take it and send it to another firm if you want.
edit: reading my own link, I see the linked to firm uses alloy moulds, I guess steel is for larger production runs where wear or heat distortion is an issue, either way, carving a case and its negative (the inside) from solid metal, is not that quick or easy, even in alloy.
