Neither the Bosio or Monark Nozzles are going to meet your time frame.

If you get Bosch rebuilds they are going to have the Made in India Nozzles that do not have a good reputation for longevity.

About 2 years ago was the last time I bought Injectors at the Junk Yard; then they were $5 each. You could use them as the cores for someone else to rebuild.
But, you would have to go down to the Yard an Pull them.

You might luck out and get some on eBay but I am guessing the Cost would be more.

There was someone on eBay selling rebuilt Injectors outright that had Monark Nozzles but I have not kept up with the latest on that.

With any Injectors purchased on the Internet if you have a problem with one or more you are not going to meet your time frame.

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84 300D, 82 Volvo 244Gl Diesel