$2500-3000k to replace it is cheaper than the alternative mate.
My mechanic was telling me he was looking after 3 fleet vehicles that got passed on to the business owners sons and they slacked off on the maintenance once passed on at about 100K km mark, all yd25's, they had about 130, 160 & 180km on them. The one at 160km's had a timing chain let go, everything destroyed (as in neither the top end nor the bottom end was salvagable), ended up spending about $17k on a new motor, i'm assuming that was the total bill for the in/out replacement plus the price from Nissan.
Between this issue, the price of the injectors to replace and weak clutches i couldn't bring myself to buy a YD25 vehicle myself. Opted for the D22 3Ltr instead, at the cost of horrible torsion bar suspension!
I'm not trying to bag the YD25 here, just tryna help you feel justified in the repairs/inspection