The next cost Tesla will raise is the $1200 destination fee probably.Something to keep in mind while waiting is that oil prices are going up. That's going to increase the cost of delivery by diesel transporter trucks. I'm sure Tesla is already trying to pack a transporter full any time it leaves Fremont (or Austin), but they must be getting even tighter now that transport costs are increasing. So if there are 15 cars ordered from Buffalo, New York, and one transporter can take a maximum of 10 cars, then the first 10 will get VINs because they can go as a group to Buffalo. But the last 5 may have to wait for another 5 vehicles to be ordered before they'll get VINs.
If Tesla is being really pedantic about shipping costs, they may sit on 9 orders coming from one city just because they can fulfill 10 orders from another. Note that if you or I ship a car across the country, it'll be around $1000. Probably more with oil prices going up. Tesla can probably manage half that, but it's still an unwanted cost.
The moral of the story is to order 10 Teslas at a time.
Edit:
Apparently Tesla ships by rail, so now you have to buy 100 Teslas to fill a train. (By the way, 10 Teslas is actually cheaper than a house in Fremont, CA...)
Kidding aside, I'm sure they ship them to a regional terminal, then split them up by destination. So everything in your region can be collected together, but the trucking point still stands, though it's less of a factor.
Edit - The $1125 destination charge. The $1200 above includes a $75 doc fee.