I am married but not in the elder category… loooooonnnnnggg way to go 
and oh please :halo: !! don’t give a politically correct answer “give what you can afford”
let me be precise - what amount is right for a co-worker who is getting married? You are invited just because you work together - and you know for sure once you quit job there is no way you will be intouch
then what? how much would you give?