I can assure you - there is no engine imported from Afghanistan. - so I dont know where you would buy a turbo from Kabul.
there is a small market selling turbochargers - new and used in Ruby Plaza (next to plaza market) - they sometimes have new assemblies or the repair kits for some turbos - they usually deal in huge industrial units but I have bought new holset and Garett automotive purpose units from there too.
new turbocharger assembly is not cheap, its price might shock you.
You can try your luck with a scrap market engine turbo, its a hit or miss - and highly depends on the term of purchase you set with the seller.