The Boker switchblades are really cheaply made Chinese conversion to switchblades. There not legal at all to import as switchblades, and is a Federal Offense....nothing like importing a >5mw Laser, you'll do serious time in the slammer for importing a switch blade into the USA. What usually happens is, they are imported as a regular knife, then a conversion is done on them by the importer.
Once that conversion has been performed, it would be a Federal Offense to ship them across any State lines. Also depending on where you live, many States will charge you with a Felony if you get caught with one.
The only exceptions to this Federal statue is for Police Officers & Military.
The ones you posted on DX do appear to be simple folders though and you shouldn't really have any problems getting it.
If your State allows, and you can find a dealer located within your State, then you can purchase a switchblade, but I'd stay away from Chinese conversions though; they are very cheaply made and are not reliable; you'll find them around the $50.00 or lower price range, a dead give away.
Also remember if your State does allow you to own a switchblade, you probably will still be prohibited from having it on your person or vehicle; so you basically can only use it in your house.
There are a few States, usually with permits, that will allow you to carry one on your person; similar to carrying a handgun.
Go to this site, and you'll find quality American made automatics that a very reliable;
http://www.microtechknives.com/
Fortunately where I live they are legal with permits to carry or just to purchase w/o, there are several local dealers within the State that sell them along with other quality brands, and sadly yes they also carry the cheaply made bokers and other Chinese origin ones.
The bokers sold on DX are copies/clones what ever you like to call them.
knives4wholesale also sells many copies/clones too, and unless you live in Florida where knives4wholesale is located, or you are a Police Officer, it is a Federal Offense to purchase from them. They do sell some genuine products, but most of their stuff is cheap Chinese fakes.
Please do yourself a favor and read their FAQ;
http://www.knives4wholesale.com/terms.html
If you don't live in Florida and you place an order from them, you've agreed you are a Police Officer and if your not; you could be very easily charged with 2 Felonies. UPS, their records, and your credit card will be all the proof the government would need to to go after you....and OMG IF you had them shipped via USPS, add-in another Felony.
Seriously think about it before you place any order with them for an automatic.
-Stay safe
Get the second one 
Almost but not quite, & that one costs a HELL of a lot LESS than my BOKER 
