I wanted the low end 2011 Mac mini with more RAM and an SSD. I'm price sensitive and Apple's custom options were too expensive. I bought the mini from Amazon ($30 cheaper than buying direct), upgraded to 8GB RAM ($40) and added a 128GB SSD ($175) using this kit ($70). Total cost: $855
It definitely wasn't as quick or easy as the video made it look, but it wasn't terrible. I was being insanely careful, so this probably took me just over an hour.
If you're taking a single HD mini and *adding* an SSD to do a clean install of the OS and use as the boot drive, don't worry about swapping the drives' placement. You can install the SSD in the second slot, connect it to the second SATA connector, and install Lion onto it and set it as the boot drive with no problems or performance hits.