Just got Witcher 3 for R400 off TakeAlot using their vouchercloud vouchers. I do believe that's the cheapest yet unless you're buying Russian keys.
Having the physical disks and being able to install it instead of waiting for a slow download/preload is much nicer.
Well 25euros is just over R300?
I would rather sacrifice the extra 100-200 bucks and buy from a reputable retailer/service.