Um yeah, no... "Holiday Sale tickets are not eligible to be resold through the Secure Ticket Exchange Program (STEP)." http://tickets.burningman.com/
Holiday tickets aren't eligible to be sold in STEP--but Holiday tickets are fully transferrable and eligible for name changes. So, you can buy Holiday tickets from someone, but when you're satisfied that the transaction has worked, you have to opt out of STEP as soon as possible.
If a person sells you Will Call tickets (all international orders are Will Call), the order cannot be split up into 4 names, hence his request to sell them all together. (They can be transferred into ONE new name, & the person who picks them up at Will Call can put the other 3 into other names).
That said, he's got one more ticket than you actually need, and having a Will Call order transferred into your name requires a form be filled out, and some way of trusting that the person will indeed transfer the tickets as promised. See Will Call
and Avoiding Fraud & Buying Third Party Tickets