I've tipped exactly the same (50 euro) in Spain before in the past so it's not that uncommon and as you say Christian that IS cheaper than Bangkok, which is why a lot of people seem to be changing holiday plans as I know I certainly got sick of the wham bam thank you mam conveyor belt attitude in Thailand, with the Thai guys just waiting for the next sucker to come along ( no pun intended).
Or as SG has already mentioned the "vodka" and coke type drinks with the vodka maybe being rubbed around the rim of the (tiniest possible ) glass, all oaded with ice and next to damn all vodka etc in it anyway or so little it made no difference to the taste etc and all for the "special" (high) prices they charge.
Actually my mate has just arrived in Bangkok just today from the UK and both he and another friend of his who travelled seperately on two different airlines reported one plane was no more than half full and the other only one quarter full ! SO if that's anything like the norm this week as to the number of people travelling to Thailand in general it'll be interesting to see how the "high" season pans out this year ?