Most commissioned DayZ work is invisible. It ships straight to one server, stays private, and leaves the person who built it with nothing to point at. This is where that work gets a portfolio and a price.
A mod that went to one paying server is still the best proof of what you can do. List it as a showcase - screenshots, a clip, what it does, who it was for if they are happy to be named - and mark it private or commission-only so nobody arrives expecting a download link.
Public Workshop uploads belong here too, and you can prove they are yours by signing in with the Steam account that published them.
A reputation is only useful if it is hard to fake, in both directions. Reviews from members with both Steam and Discord linked count at full weight; a single linked account counts at half weight. Every review is labelled with exactly which accounts stand behind it.
That cuts both ways on purpose: a rival cannot bury you with throwaway accounts, and you cannot inflate yourself with them either. The number beside your name means something because of what it refuses to count.
Nothing, and there is no mechanism for it to cost anything later. No listing fee, no featured slot, no commission on your work. Payment never touches this site - you and your client arrange that between yourselves, exactly as you do now.
That is partly principle and partly the licence: DayZ modding sits under Bohemia's rules, and a site taking a cut of mod work would be a problem for everyone on it.
The people hiring are server owners, and this site is built around them: 218,119 of the servers we track are running mods, which means someone had to build or configure those.
The creator side is new, and it would be dishonest to pretend otherwise - there is no crowd of listings to get lost in yet. That is the argument for being early rather than against it: the first profiles here are the ones people find.