I will ask Paul today. Usually when I ask where he gets components he replies Mauser or DigiKey. Keep in mind though that the reason the Teensy is so limited is that Paul is unable to find any more of the chips out there from any supplier he can find. Basically between JIT inventory strategies, the economic recovery starting to spin up and the out-of-left-field sudden huge demand for the product basically there is a global run on the chip until the manufacturer can arrange for fab space to make another run on them. Simply put the Teensy was not designed for the purposes that gamers are using them for and no one anticipated this sort of dramatic increase in demand.
Granted, when Paul is sourcing components he is buying reels of them so that the product can be made in numbers, so I am assuming he is ignoring suppliers that have less than a certain number of the chip. I am -guessing- that if you are lucky you might find some left in someones parts bin somewhere. I'm sure though that Paul would just give me one of his "not likely" looks and say "Maaaaaaybe".