If you stand in front of it, the stock changes every 20 minutes. Once you leave, it’s gone until next week. I managed to get a Super Shreddiffier with my Fl4k’s last dollars. I’ve got 4 VHs that farm Maurice’s machine every week.
It’s never come back for me either. Next Thursday, when the new location is found, try my method. If you don’t leave you can buy until you run out of money as the machine is reset with new stock. Where is Maurice is the website that posts the location.
The cooldown timer is 30 minutes in-game time per character. Go do something else (farming, side missions, etc.) and the vendor will return. It doesn’t matter if you buy anything or not; it only counts if you view the inventory.
That said, I’ve found that sometimes the vendor will have exactly the same items as a previous visit. Closing out the game entirely seems to reset this (but not always).
Like the original poster and second responder, regardless of in-game elapsed time, save quitting, and coming back, once I have purchased from Maurice’s Black Market with a character, the vendor no longer spawns in that location.
My initial assumption was that the vendor moves to another location once you’ve used it, which would fit the theme. That said I have never seen it twice on a character, in a weak, after making a purchase. The one and done phenomena is consistent with my experience on my 4 main characters.
if you loiter in front of the machine, the stock will eventually change. I did this yesterday with my Fl4k. I ended up spending everything in his bank to buy various flavors of Shreddifiers & Rowans Calls. Once you leave the area, Maurice’s machine is gone. If it does come back, it’s never happened to me. Just like Red Chests are supposed to reset after 20 minutes, it never happens.
Tested again today, and initially it spawned for all four. After some mobbing, bossing, and Bank purging, Mule loading, it only respawned for two of the four. I’ll try again in the evening.
Yeah it’s supposed to be on a cooldown timer like red chests, but like was the case with those chests, I guess it’s not impossible for the cooldown for the vendor to glitch out in some way on particular character save files or whatnot.
(Side note: I still kinda miss having glitched cooldown red chests. In this case, there was no cooldown and I could quit/save farm red chests to my heart’s content with my Moze. Alas, no longer the case. )
Sometimes red chest will glitch, so I guess the Maurice machine can to. If I had a chest glitch, I could usually get it to reset by waiting the 30 minutes and visiting several different maps. Usually after 4 different map visits, the chest would reset. Might work here.