I'm interested to know where and how you are getting hold of a bulk of Pr:YLF. They are not cheap nor accessible usually. This is the only place I have found that offers them to the point you know the price.
https://4lasers.com/en/components/crystals/laser-crystals/pr-ylf-crystals
480 € (~$550) for a 2x2x6 crystal. So your system including optics, crystal and pump diode doesn't leave much room within that $700-800 asking price. Are you getting your crystals out of salvaged systems or have you got a cheap supplier?
I know for most 607nm would be most desirable. 523nm is covered by diodes so only those really wanting a Pr:YLF DPSS will be intrigued into paying for it. If you are able to make 607's for a reasonable price, I know you'll likely have some takers.