It's one of those grey area domains.. it nearly makes sense and passes a few bars but kind of turns out to be one I'd pass on, giving it low value. You could still find a buyer, of course, or a use for it yourself which pays well over time somehow. But I see too many better opportunities at present to begin seeing a domain like this as having over-par value based upon even scarcity alone.
Things that would make a better domain:
I'd overlook it because it's hyphenated
I'd only want the .com.au (rather than .net.au)
I'd prefer the singular - the plural doesn't work out on this domain to me (even if CPC and search is slightly higher, it's only marginally so - and so it's one to overlook given the two criteria above.
The next better term would be 'web designer' - better global search and it's shorter (less confusion).
It might appeal to someone wanting to develop a site highlighting designers, maybe a blog.
The singular might make a slightly better value proposition to a web designer.
The domain website-designer.net.au - is parked (no use)
The domain web-designer.net.au - account suspended
I don't like where that's heading..
My view is keep looking for buyers, but don't expect it to be in a highly competitive space.
Cheers.