Cheap PC Oscilloscopes - Any Recommendations?

Missionary Man asks: "I'm an electronics teacher looking for a good (but reasonably cheap) PC based oscilloscope for classroom demonstration purposes. I've done a reasonable amount of research and come up with a few contenders. Ideally I'd like something with a bandwidth of up to 40MHz and 2 channels. Does anyone have any tales to tell regarding the use of any of these scopes (or any others I haven't found or mentioned) and can recommend a suitable device?"

"Here's the list of my findings so far:

• The DS2200C from USB Instruments will do 2 channels at 12 bit resolution, but only to 200KHz.
• The PCS100 from Velleman at QKits runs to 12MHz, but only 1 channel. It has a bigger brother, the PCS500, that has 2 channels and 50MHz bandwidth, but is a lot more expensive.
• Picotech do cheaper ones, like the ADC-40/42, but these only operate in the KHz ranges.
• Link Instruments sell the DSO-2102S that runs to 60MHz with 2 channels, but it's a bit out of my price range.
• Finally, I found the bitscope which seems to be just what I'm looking for, combining a 2 channel scope and an 8 channel logic analyzer for a reasonable price.

I'm hoping to spend US$300-$400. I recognize the software is a fundamental part of the successful operation of these units and any comments regarding the bundled programs would be most helpful too!"

Comments

Yeah, Um...

[dupper]

I have no experience or contact with oscilloscopes, so would someone please inform me why they cost so damned much, even used (and up to friggin $20K, new!). Yeah, thanks.