Affordable Source Measure Unit Alternatives to Keithley 2400 for Hobbyist Labs

I have some nice instruments in my home lab, but what I do not have is a nice source measure unit. I have used the Keithley units in the past, and they are great to have around. It makes testing analog circuits, opamp and the like a breeze. Now that I do not have one, I am missing it. I want to test out my opamp circuits across a voltage range. I know I can find a voltage in a lot of places, simple power supply, etc. I'm just wondering what options might exist for doing the types of things that a Keithley does, but at a lower cost, more of a hobbyist cost. A used Keithley 2400 is > $3K.

The only thing I've seen that's remotely affordable is maybe something from Datatranslation.

http://www.datatranslation.com/products/dataacquisition/usb/dt9853.asp

However, this is nowhere close to the power of a Keithly.

I'm thinking there's a good market for a small player to make a USB source meter with halfway decent specs.