Pretty sure this fine as per licence, though arguably unethical.

For software under that licens, you are alowed to take money for what you put into distributing the software.
Wich translates into, that it's ok to take money for your time, for the media you distribute it on and stuff like that.

That's how you make money on open source and so on.

Not quite:

Since free software is not a matter of price, a low price doesn't make the software free, or even closer to free. So if you are redistributing copies of free software, you might as well charge a substantial fee and make some money. Redistributing free software is a good and legitimate activity; if you do it, you might as well make a profit from it.

https://www.gnu.org/philosophy/selling.en.html

What they're doing is sleezy, but it's probably not illegal as long as they're including the information in the GPL and providing information on accessing the source code of everything they've shipped.

At that price they're not really making much money. The disk 2-3$ the print on the disk is maybe 1-2$ then you have 10% fees on eBay and 3% on PayPal. That's like 5$ at best. Add time, risk and the power used to burn the disk they probably have like 2-3$

That aside sometimes it's nice to have even a free pice of software on a disk. And there are times that you need it on a disk.
I ran into a point were I did not have a running system and needed an OS disk and bought a copy of cent OS on a cd from my phone.

Edit:
The shipping is free too. I don't see them making anything over a dollar.

This has been discussed before, and the consensus is that it's not illegal, just questionably useful.

And if they are doing anything other than burning the DOS Box installer to disc, they have to make their changes available under the license.

They would have to publish any source code changes as well as (arguably) any build script infrastructure. Installation tools and shells would be exempt from that requirement as they wouldn't be a derivative work. They would be packaging around the GPL software.

Not like I think anything such as that has been included.

Dosbox 0.74 is 1.4MB... it's free and even downloadable with a 14.4kbps modem easily (If anyone STILL using them.)

I am absolutely speechless .... the unscrupulous seller .... and the poor souls who bought them...

Malik wrote:

Dosbox 0.74 is 1.4MB... it's free and even downloadable with a 14.4kbps modem easily (If anyone STILL using them.)

Well, if one is using a 14.4kbps modem, finding out about dosbox.com and browsing to it might be difficult. But then again, anyone having such extreme difficulties with browsing and downloads would likewise probably not be bidding on eBay.

I guess some people just like having physical copies of software.