1. It depends. If you received a lot of low-value outputs then it will cost more. It is possible to send 17 XMR or more for much less than 0.26 XMR, even with the default fee (around 0.014 XMR is a typical fee on the network right now), if it isn't made up of a lot of small pieces.
2. Using the low priority fee setting the fee can be much lower, around 0.20 EUR, but the wait for confirmation will be longer during periods of high load.
@pönde moneroblocks and chainradar are both broken. xmrchain.net and minergate.com/blockchain/xmr/blocks appear to be working. Your own wallet was probably correct.
Thanks for the info...