These are quite cheap and are offered as an alternative to downloading & verifying the ISOs yourself; useful where internet access is restricted (capped, metered etc.), slow &/or unreliable.
It might be closer, but quite often ISOs are downloaded but never used (I recently found a set of unused Ubuntu 12.04 disks), tried a few times & forgotten or just downloaded out of curiosity.
There are also those of us who get the whole set of ISOs for our chosen distros but only actually end up using a few of them for ourselves, the rest being for testing in VMs, possible distribution etc..
Very good point!
It does take a bit of acclimatization, along with yaourt & the sometimes large choices of package versions & sources ...
I'm using it now on my other machine, one thing I can say is it's really fast even on such limited hardware. There are, however, a few issues to sort out before I can call it fully set up. (KVM refuses to work though it did in Mint, for one thing).