Need Help with Stepper Power Supplies

I'm finding that a 40V to 60V 10A power supply for the steppers is
not inexpensive (under about $70). Standard PC power supplies have
12V at about 10A available. I think it might be possible to connect
5 of these in series to get 60V at 10A. I can get PC supplies for
about $5. Is this a good idea?

I checked two PC supplies that I have. On one the 12V ground is
connected to the chassis. On the other one it's not. Since the
ground wire from the AC cord is also connected to the chassis, I
can't put multiple supplies in series if they have the 12V ground on
the chassis as that would short them out. Can the 12V ground be
safely removed from the chassis?

I have also looked at building my own linear power supply, but an
appropriate transformer (40V 10 or more amps) is very expensive.
Short of rewinding a microwave transformer does anyone have any
other ideas?

I know it sounds cheap to try to get away with spending $25 on a
power supply, but after I buy the steppers, the drives and the
material to build motor mounts there's not much money left.

Any help would be appreciated.