It’s certainly not a scam, but it’s definitely not as good as it sounds.
For one thing, if this fonts CD is like the ones I’ve got, you won’t be getting 8,000 completely different fonts. What you’ll be getting is several different variations of the same typeface.
For example, take the font Serif. Most likely, that will include Serif Regular, Serif Italic, Serif Bold, Serif Italic Bold, Serif Compacted, Serif Extended, Serif Compacted Italic, Serif Extended Italic, and so on. There may be as many as six or seven fonts based on the basic Serif design. They all belong to the Serif font family, but each variation is counted towards the 8,000.
So the 8,000 number is a bit of a misrepresentation. There’s 8,000 fonts, sure, but as far as distinguishably different typeface families, you’re probably getting only a fourth or fifth of that. My 3,000 fonts CD, for example, has only 500 distinct typefaces, but each has six variations.
I just took a look at the Font Showcase link on that page, and there are just under 100 font samples there. I strongly suspect that those are a good majority, if not all, of the fonts you’ll be getting on the CD.
In addition to the one-for-price-of-six thing, some of the font familes themselves may closely resemble one another. In another (particularly poor) CD of mine, about half of the fonts looked alike. The samples printed on the CD cover were the typefaces that were clearly different from the rest. But of the 500 or so fonts in that CD, I had only 100 truly unique fonts.
As RealityChuck and handy have noted, you can find tons of free fonts on the Internet. However, I don’t recommend that if you don’t have a strong tolerance for flashy banners and pop-up windows. Many free fonts sites, especially the portal sites, have way too many of both. It can also take a while to wade through links and find fonts you like.
On the other hand, if you know what kind of font you want (dingbat, uncial, blackletter, etc.), then the Internet’s a damn fine resource. But if you don’t know what you want, or if it’s a pain-free font-shopping experience you want, then those CDs are the way to go.
I also echo astro’s don’t-install-too-many-fonts warning. Pick a handful of your favourites, or only the ones you’ll need, and install just those. Remember, you have a CD to back you up; you don’t need to install them all, and you can always reinstall a font or two later if you have to.