Gareth probably isn't allowed to answer that directly, but maybe I can give a general indication that may work for SOME developers/supporters, though certainly not all.
Take a look at the person's profile, look at some of the plugins they have developed. SOMEtimes there may be sponsorship or 'support my work' links on some of those free plugins which you may be able to use to support those who give up their valuable time and effort (as you point out) in this community.
[Pointing out just for the sake of ensuring no-one thinks I'm posting this for personal reasons, no such links on any of my work
I've always been very fortunate to work for organisations that support my minor inputs to the community eg. my community theme building has often been experimenting and stepping stones towards themes built for work. ]
Take a look at the person's profile, look at some of the plugins they have developed. SOMEtimes there may be sponsorship or 'support my work' links on some of those free plugins which you may be able to use to support those who give up their valuable time and effort (as you point out) in this community.
[Pointing out just for the sake of ensuring no-one thinks I'm posting this for personal reasons, no such links on any of my work