White Buffalo Racing consistantly has good prices on DID chain and either JT or Sunstar sprockets. (Sunstar is OEM manufacturer for Honda, btw) Just be sure to ask what the shipping is. Chains are heavy, and you're a ways away from California.
"The rear sprocket is in excellent condition, unknown when the front looks like, but I'm told they all should be replaced at the same time."
I guess you'd have to define "should."
For instance, your chain
should have been changed before the links started kinking.
We
should change all the sprockets and chain every 10,000 miles, just to be safe.
We
should change clutch plates and disks every 25,000 miles, just to be safe.
I could go on. And will.
The argument that all sprockets should be changed with the chain (the entire system) is valid in that one component does indeed affect the other, and any wear that a component such as the chain has will impact on the sprockets. If you renew the chain, and not the sprockets, the wear that is already on the sprockets will prematurely wear the chain, and you'll have to replace it sooner than if you did replace the entire system.
This is true.....but. It really depends on the amount of rear sprocket wear. The rear sprocket gets 1/3 the wear of the front sprocket simply by virtue of going around three times slower. Also, the accelerative loads on the rear sprocket (both positive and negative) are transferred over a greater area of surface, and therefore not as damaging.
You should always examine your sprocket for signs of wear before making the decision to retain or renew. Typically, an XX rear sprocket lasts for 2 to 3 chains, and a chain lasts 15-17 thousand miles. No one can predict the environment your chain runs in, or the level of maintainance you use, so YMMV.
Purely guesswork...if the chain wears out 10% faster because of a damaged rear sprocket that you cheaped out on and didn't replace because it cost $50 and an extra hour's labor....doesn't that come to about $15 negative on a $130 chain?
Your call. Each side of the argument wears validity.