My kitchen sink mixer tap (faucet I guess) has developed a leak.
Mixer is similarto this.

The leak occurs when the long "output" arm is swiveled, water leaks from above the arm join.
It also leaks after the water is turned off, when the handle in the centre "warm" position. This leaks water from the join below the handle. When it's off and in the "hot" position, it doesn't leak.
So,
Is it possible to repair? Is it worth the callout cost of a plumber?
Bunnings sell the one in photo for $230, this is actually a little cheaper than I expected. So perhaps easier to just replace with shiny new unit. Should I attempt to install myself?
I am a reasonably competent handyman, but I as this is critical household infrastructure, perhaps better left to a professional. Thoughts?
And finally, and recommendations for good plumber in west Auckland?
Thanks,
Cheers,
Joseph.