... In Germany the restaurants and hotels are much cheaper than in the rest of West Europe.
Like in: Double the price than in other parts of West Europe.
At least, my experience till 2010, in developed parts of Germany, parts with de-facto employment opportunities.
With products from outside the EU the importer becomes liable so a smart importer makes sure he gets documents from a qualified testing facility which proof the product has been tested. So in general the self-certification is a no-go for imported stuff.
With products from inside EU the buyer is responsible too. No difference.
Something else popped into my mind: how about CE when dealing with the UK in case of a Brexit?...
Your mind invoked another unnecessary unexisting problem.
Manufacturer makes product, chooses to certify CE or chooses to not certify and sell it with a workaround as experimental of not-working.
Buyer buys with CE to be ready to sell/integrate or without CE and does everything himself.
No difference if the buyer buys it in Germany of Serbia.
No diference if the manufacturer sells it from Germany or Serbia.