Profit for who?
Cheap stuff (say, up to about 100 euros) you buy in shops have about 50% markup at the shop (that is, the shop gets around 50% of the price). From that, the shops have to pay their rent, their employees and all other overhead. What's left over is profit for the shops.
The other 50% goes to whoever sells the shop the items.
Actually, that's not quite right: sales tax/VAT takes 20% or so off the top, but that cost is spread around. It's more instructive to just ignore VAT all together and concentrate on the tax-less costs (which is why business-to-business pricing is pretty much always specified without taxes*).
You have to look at the supply chain:
Shop (Local store) <- Franchise organization, if any (Amazingly amazing computers international) <- Importer / Wholesale (may be combined with franchise) <- Manufacturer (Filco) <- Manufacturer of parts or materials [ repeat this stage ] <- Base resources (Metal ore, Crude oil for plastics etc)
At every stage in this process some profit is made (don't forget shipping!) and the consumer price will go up, or the company involved will eventually go bankrupt. Also, larger quantities are cheaper at every stage (for example, a single full set of cherry switches without caps is about as expensive as a fully assembled Filco board, but Maltron claims they buy them for 20 pence each - which is still around 25 euros for a full set).
Also, manufacturing of plastic parts traditionally has a high startup cost because you have to make molds (IIRC on the order of 100,000 euros for larger parts). Not a problem if you're selling millions of items, but that really drives up the cost if you're only selling a few hundred a month. The same is probably true if you want specifically designed metal parts like springs etc - you need to pay for the tooling to make them.
What all of that means is that if you make products out of more (and more intricate) parts, and you want quality guarantees, and you're not selling the items as part of a bigger package, it's going to cost money. Quite a lot more money.
Whoever made the humble hacker board here said those things would cost something like $100 for the plastic enclosure alone for small runs. And that's with innovative "cheap" small-run plastics manufacturing. Add in assembly, controller and switches and you're up to $400 in cost (no profit for the manufacturer yet, and it still has to be sold to consumers too).
If on the other hand you've got 500,000 PCs to sell and you just need "a mouse" and "a keyboard" to go with it, you're going to look for the absolute cheapest **** that people will still accept - probably meaning you build the thing out of a single PCB, one rubbery layer for the domes and the cheapest enclosure and key caps you can find - and you don't care if it breaks in 6 months. You're probably not even interested in making a profit on the keyboard - you're going for profit on the total package.
All in all, I'd be surprised if Filco made more than 20 euros profit on each board they sell, unless they're selling way more in Asia than they appear to do in Western Europe or the US.
* for the Americans, in most countries in Europe VAT is at a fixed rate (per type of product) throughout the country and consumer prices are specified with sales tax included.
