Pathways Into Darkness v1.0 went on sale at the Boston Macworld Expo on August 3rd 1993. According to the Pathways v1.1 -> v2.0 updater Read Me Bungie sold 350 copies at the show. The Read Me states:

If you are one of the 350 people who bought Pathways 1.0 at MacWorld Boston last year and never received the version 1.1 updater, you will need to use that before you can run this updater.

According to Tuncer Deniz in a Making of Pathways Into Darkness article for Inside Mac Games (Dec '93) 500 copies of Pathways v1.0 were duplicated and shrinkwrapped in the offices of Bungie Software for sale at Macworld. The article relates the following:

By July, only the pyramid was finished, but all the levels underground remained to be created. The game was behind schedule and the pressure was on to ship by Macworld. Jones worked feverishly putting in 18 hour days, and rumor has it that Jones suffered a nervous breakdown (I'm just kidding). By the end of July most of the game was finished, and went into beta about a week before the Expo. Just before leaving for Macworld, 500 copies of Pathways were duplicated and shrinkwrapped in the offices of Bungie Software for sale at the show. Despite the rush at the end, the program came out relatively bug-free, thanks to Jones' careful programming.

So the rush was on in that final month leading up to the Boston Macworld Expo '93. Indeed there is an easter egg of sorts in the game about the rush to finish on time. If you ask the dead Special Forces guy called Jason on "Need A Light" about 'pathways' you get the following response:

I'm coding this script in the afternoon of
July 22nd, do you think we'll make MacWorld
on August 3rd?

Now if that's not cutting it close I don't know what is.

Pathways Into Darkness v1.0 was sufficiently buggy enough to warrant an update shortly after going on sale at the Boston Macworld Expo. The Pathways v1.0 -> v1.1 updater Read Me informed us:

Version 1.1 is an update to Pathways that fixes some minor bugs associated with Multiple Monitors, window positioning, copy protection, and the restore command.

The Pathways v1.1 -> v2.0 updater Read Me would suggest that only 350 copies of Pathways 1.0 were ever sold. Copies shipped out by Bungie after Boston MacWorld were most likely the updated Pathways v1.1.

As such, Pathways v1.0 is a rare (albeit buggy) collectors item.