But it would be an Olhausen and not a Diamond. Try looking for a used 9' Diamond. You will be more likely to come across Pro-Ams than Olhausens at local pool halls.
Best deal many of us have found for the Aramith Tournament (Duramith) set.
https://www.wayfair.com/furniture/pdp/aramith-16-piece-super-tournement-billiard-ball-set-amh10007.html
I have purchased from Go Custon Cues and the products and customer service have been great. There does seem to be a problem with their website this morning. They are located in The Netherlands I believe.
An older link:
https://forums.azbilliards.com/threads/go-customs-carbon-fiber-cues.518730/
You would be doing us a great favor if you could post an instructional video about the correct way to chalk. Obviously, nobody here, besides you of course, knows how to chalk properly and your gentle guidance would be appreciated.
It does last a long time. I think one reason is because much of it is not wasted falling to the table, floor or shaft, instead of adhering to the tip. The only V10 used is the chalk applied to the tip.