DX has got a new light Ultrafire M5 with a ww MC-E dropin http://www.dealextreme.com/details.dx/sku.47351
Looks like the Skyray from LT which has a R4 for 27$. The new one from DX cost only 23.40$, which means
that you nearly get the host for free, as the MC-E dropin are 20.85$.
The thing is, not all drop-ins are created equal. There seems to be a bunch of these cheapo warm mc-e's going around. I got one as part of $20 light with a Solarfarce body. We'll see how these go, but if it's like the cheapo 5mode xp-g I got, it might even be direct drive.
Another thing to note is that mc-e's should cost >$10 in 1000's quantities, and in order to ship them to customer for around $20, the lights themselves have to be <$13-14 or so. Factor in even minimal profit for the parties involved, and you can make guesses as to what got cut.