Quantity makes a big discount - if you order a 1000, instead of one it will be cheaper per unit . To sort out , pick , wrapAnd process the paperwork is a fixed cost - whether you buy one or a 1000. If you buy one,that's probably most of its price
Are the chinese really producing in that large of a quantity to justify that price? Or are they using knock off micro controllers?
ST and Freescale (now NXP) are perfectly fine about having totally different prices in Shenzhen / Taiwan than in the EU / US, particularly for the extremely popular ICs. the STM32L471VG for example can be bought on taobao (the equivalent of ebay) for around $2, $2.50, when the "list" price is actually around the $5 mark. the STM32F103VCT6 was available many years ago for $1 when it was at least $3 outside of Shenzhen.