I just picked up a few par 64’s from:
https://rstvisions.com/pages/contact-us
They were $305/each, ask for Marisela. I may have bought the last they had in stock but it sounds like they can get more. I couldn’t find a better price out there..
Another option i stumbled onto when i was exhausting the internet for bulb options was this place that converts par 64 fixtures to work with the SE g38 bulbs:
http://www.galaxylightingrepair.com/HMI_Repair_Special.html
Cheers!
Brian Chism