M92 by onyx-boox.com is not the same as eReader (or some other stores). (I mean, it is the same hardware
, but it has different firmware and different accessories and different lenght of warranty)
It does not have cover and warranty is 1 year (eReader 2 years), but it has better TTS (text to speach) software and some cloud ability a maybe few more things. The most important difference (for certain users) is that you cannot use "Booxstor's" firmware, but one by owner of onyx-boox.com.
So, it is up to you, what you prefer.... And you need to add a good
cover, so the price difference will be a bit smaller...
Also, geekbook.cz has good price, which is about 280 EUR +VAT. But their pages are only in Czech and I do not know if they sell international.
Another option is refurbished returned pieces. Booxtor wrote in another thread that he has few pieces for sale at 20% discount price with 2 year warranty. So, if you do not need a brand new piece, it might be an option.