I grew up in Warkworth. Wellsford hasn't changed much in all those years - I still can't think of any reason I'd want to live there, even though property is more affordable there. I've heard that when (if?) the motorway is continued from Puhoi to Wellsford, the area might experience a boom, but it's my understanding the C'Ch earthquake will delay the motorway project.
I got an email from a Warkworth realtor last week who asked me if I'd thought of looking at property in Wellsford. He lives there and loves it. His name is Peter Marsh
http://www.barfoot.co.nz/p.marsh He might be a good resource for you.
It's about 45 minutes from W'worth to Auckland....and an additional 18 to 20 minutes to Wellsford, (I just timed the WW to WF trip in March), assuming you don't have traffic. A BIG factor to consider is traffic coming south on the motorway in the summer when everyone is heading back to Auckland. Then the 1+ hour can take hours.