$899 seems like a fair price for a used Sherline micro-mill with CNC. The freight charge hurts.
Compare to about $500 (on sale) for a new Harbor Freight mini-mill - non-CNC. Better capacity than the Sherline, but lower quality and no CNC.
If you're a tweaker, though, you could make it into a nice CNC mini-mill for about the same price ($1200).