Price is without the aliexpress warranty, with it, its £124.54(to remove the warranty change your location to USA, then change it back once you have placed it in your cart).
Think everyone knows all about this phone.
When you trying to find the best price, ensure you are comparing like with like. Sellers need to say it has B20 or 800mhz band, this is the global version. If it says global rom or international it probably isn't the 'global version'.
On aliexpress there is no official Xiaomi stores, there are a few stores that pretend to be, they are all just retailers.
For cases and screen protectors, look for ones advertised for Redmi Note 4X or that specify Global Version Redmi Note 4. Snapdragon model has updated housing but cases advertised as 'Redmi Note 4' will most likely be for the original Mediatek housing, and won't fit this phone correctly.
NB: Silver option not available.