Hegner makes a great saw, and has for years. With any used tool, check for damages caused by shipping or moving. Put a blade in and slow the speed to its lowest setting. Make sure that the blades goes straight up and down as far as left/right movement. This will insure that the upper arm is aligned with the lower. Make sure there isn't excessive back and forth movement as well, although most saws have some as a design element. The saw should be close to vibration free at all speeds and operate with little noise. If those things check out and the price is right, you've got a great tool.
And that's my 2 cents worth!