[djmcmath]

You can get a pretty good single-boiler machine for about $150. Anything less and you're probably not going to be able to achieve decent espresso -- poor temperature control, poor pressure control, etc. For another $30 or $40 on top of that, you can add a PID controller to your $150 machine and get substantially better temperature control for noticeably better espresso.

The other expense you need to consider is the grinder. Another $150 will get a burr grinder that won't frustrate you a lot, but won't necessarily give you the consistency to get good shots routinely. If that's too much, then you can do passable coffee buying pre-ground from a local roaster.

But then, that's coming from a guy who roasts his own beans and spent close to $1200 on his current espresso production setup ...