As a sidebar to this...If you buy from an individual make sure the title is "clean" and there are no loans or liens against the bike.
That would be a real pain if you made an out of State purchase, went to the expense to get it home, attempted to register it and then learned there was a loan on the bike that needs to be cleared before you can register it in your name. Clearing a "cloud" on a title can be a real pain.
Most titles are clearly marked or are printed in a different color if a lien is in place. If a seller shows you the title and if it shows a lien, even if they stated it has been paid off and they are blaming the State that the new title has not been received...be suspicious. While I'm not a Lawyer, you could be adopting someone else's loan balance. (Sorry, to sound like a conspiracy theorists, but there's a lot of money in play for this type of purchase and attempting to save a some big bucks by buying used directly from a seller does come with its share of risk).
Another factor to consider is that once you've selected the bike you want to buy, get the VIN and contact your insurance agent. He/She will be able to give you a quote within minutes and if there's any funny business going on with the bike (previously wrecked, stolen, repo'd, etc.), it will most likely come up when the Insurance Company checks it out.
As discussed in other threads, with insurance, you'll get what you pay for.
On a somewhat related note, while we've all heard about those overseas scams where a fake Cashier's Check temporarily fools a bank (and the seller), sellers need to be cautious as well to make sure that they are not getting scammed when selling a bike. The only fool-proof way of making sure that the funds are "real" is to have the money wire-transferred at the time of the sale. (A Seller may want to consult their Banker before completing this type of transaction).
I'm not an expert in this field, so feel free to chime-in on this topic and correct me if I'm providing less than accurate information.