Hello,
I had my timing chain replaced two months ago..and it was the guides, again. I dont see any problem waiting until you have the money, but thats what i did and after many many months the chain had nearly ate its way through the timing chain cover, which is not a cheap part. If it pierces the cover your oil and water could mix and will cause much more damage. My truck was quoted at 980 dollars without the cover and I talked him down to around 750 dollars because I do not have air conditioning..you know less stuff to deal with equating to less labor. He worked with me, but not until I confronted him on the matter. They will take what they can get.
I also heard stories of it costing between 200 and 300 dollars, but I think that is only if the chain broke, but chains rarely brake and more than likely its the guides. It is a distinct knocking noise and 22RE are famous for guides braking. Sorry, but it is expensive. Good Luck!