"on hand"...
If that means never again that would be an incredible piece of information and terrible news. I'm skeptical.

Possibly they don't have any right now?
Which node board is it? Marco has node 0 (the main board) in stock, not for $500. https://www.marcospecialties.com/pinball-parts/520-6936-01

I also see the node 1 original has been replaced with a new part number (still out of stock)
https://www.marcospecialties.com/pinball-parts/520-6967-72

To be fair, the $1300 one is discontinued, replaced by the $900 one on the right side of the posted screenshot (509-1003-01)
https://www.marcospecialties.com/control/keywordsearch?SEARCH_STRING=509-1003-01
That board is also compatible with Jurassic Park (Pro) (according to the product compatibility tab) so not likely to be unavailable any time soon.
That doesn't explain the out-of-stock issue.

Their warranty is 2 months on the electronics. It's printed near the back of the manual on the recent games I've looked at. It starts the day Stern ships to the distributor.

Screenshot_20190807-061155_1.jpg

Will you share the data you used to make that determination please?

I don't understand your point.
1) There is currently no key post in this thread.
EDIT: Post 88 by Cruster WAS marked as a key post. It was unkeyed by TigerLaw
2) The written warranty (from Stern) on a node board is 60 days from the day it was shipped to the distributor.
3) Moderators are not usually the ones that mark key posts. Pinside editors are.