Once you add a decent spindle (and if you want to do aluminum, maybe a speed controller for it as well), you will still be under your $1500 budget with this: FireBall V90 CNC Router - This would be a perfect fit for wood, acrylic, and PCB work. If you take very shallow DOC, it would be fine for aluminum "out of the box" using a Bosch Colt trim router too.

Alternatively, get in touch with John Hansford (he actually crated the V90 design) and get one of his newer designs... microcarve MV3