clicking sound, transfer case coupler?
 

I'm thrilled to have stumbled across this website I have a 2004 Lexus GX 470 with 230,000 miles. I just paid $900 to have the front axle shafts replaced about one month ago. Its still making a noise. My mechanic said the problem is the coupler inside the transfer case. Have to buy the whole transfer case cause 2004 Lexus didn't make a replacement coupler. Bottom line is I'm looking at $2000 repair. Do I ditch the car or keep pouring money into repairs. What would you do? Thanks in advance for all suggestions and comments.
https://cimg0.ibsrv.net/gimg/www.clu...5adc781cc9.jpg
Nana Kim & DJ