When to walk away from a car?

Hi Carfix, I have a 2008 Honda jazz GD with 270,000km which I've had 6 years. The clutch has just gone in it, and it needs a new WoF. I can't do the clutch myself anymore, so I have to take it to a shop.

The shop has quoted $1200 to supply and replace the clutch only, but I know it'll need the flywheel resurfaced on top of that, and the rear main has just started to weep a bit, which may as well be done at the same time. Plus the WoF on top, which I'm 90% sure it'll pass no issues. So probably looking at $1700 all up I'd guess.

I just cannot decide whether to spend well over 50% of the value of the car fixing it, or to sell as is and buy another car (was going to next year anyway, spending around 10-15k). Or do I get a WoF check first and if it passes cleanly, fix it?

What to do?