Actually, much as I hate to tell you, unless you've the nicely retail boxed shareware games, consider it worthless. And if you do have the retail boxed shareware games, consider them almost worthless.
This is why there are a few of the "Titanium Seal" shareware Apogee games on ebay at astronomical prices, with sellers thinking that they have legitimate retail releases because they're too lazy to read "SHAREWARE" on the packaging, or because they're so dishonest and think their buyers are so stupid that they'll pay the $54.95 that one guy was asking for a Duke Nukem "Sealed" copy for 6+ months (and may even still be there - I haven't looked in awhile)
So why are the shareware copies and distributions virtually worthless? Because the floppy contents do not contain the registered versions. Because the files included therein are to be found on every single shareware compilation that proliferated the CD-ROM market in the early-mid 1990's, are given away on the 3d-Relams site now, and are available for free download all over the net as shareware, as 3d-Realms still actively protects their copyrighted games, even though the vast majority of them are unplayable on modern machines without a virtual environment.
If you've got the registered shareware floppies of any shareware game, but especially those from Apogee or Epic prior to the retail releases (i.e. the mail-ordered ones), you've gold on your hands. Not like $100/copy gold (unless it's Commander Keen - then, maybe)... but a goodly amount. And there's collectors out there that'll pay for it - Phreakindee being one of them, more than likely. Me too, if the price is right (i.e. I can't and won't afford an arm and a leg, but would go original retail or higher, depending upon completeness and condition).
I've shareware disks I bought back in the day and they're actually worth more as a "blank" floppy than as a collectible... though I keep them around simply because I did purchase them from the shareware vendors for $1/disk back in the day. To me, it's a nostalgia of the way that things used to be, same as keeping around my old Packard Bell 486 when I've much better retro systems to play with these days.
Heck, I've even an official shareware floppy distribution set from Apogee circa early 1994. It's 33 disks, and is (unfortunately) missing disk 27 (or 21 - I forget). I picked it up as a unique Apogee collectible and won with zero competition at the starting bid of $9.99. Apogee was in the title, search words, and description - as was Keen and Duke... trust me, these would have come up with any possible Apogee-related search, and it was a 10-day auction. I talked the guy into sending me the original pack-in letter and box with address labels as sent from Apogee even though he didn't want to do so as it contained old info for his old computer store. Even these copies were nothing different than what can be found on the various shareware CDs... except that they are on cool Apogee-logo'd diskettes and have 3 diskettes of screen images that Apogee hand-picked for vendors to market their games.
Outside of the logo and the screen caps diskettes, I only purchased this for the novelty-factor. It's not a gold-mine, and is worthless except to the most fervent collectors, especially in the incomplete capacity. It's amazing to me that they hadn't changed to a CD-ROM distribution by that point in time. I mean, in 1994, they could've gotten CD's pressed for what? $10-12 a piece, MAX, even in fairly small runs (say a few hundred?). Factor in the cost of floppies (figure $3-4 per 10 floppies wholesale), and the cost of shipping 33 floppies verses a single CD, and it's utterly amazing to me... the final reason that I chose to purchase the set.
I didn't recognize the Public Brand Software name, but that phone number - definitely. They're the ones who I used to call for their free catalogs so that I could drool over all the cool software and thumbnail-sized black and white screen caps - then I'd go to our local library (local being a 20-mile drive and begging my Mom to drop me off while she went grocery shopping) and I'd pull up their PC-SIG Shareware Distribution CD-ROM, and try to find all the games I wanted from this catalog and put them on my box full of floppies (that precious box - I only had one at the time.. laugh).