That is the thing, having never had one, I'm not really sure what I want/need. I'm sitting down to playing around making a front end for an AVR based frequency counter I've been playing around with for years and it occurred to me that having the ability to make a signal to test with (frequency, amplitude, etc.) would make the job easier. In this case the price is probably king, I don't want to spend too much. I've got one of those dds boards form ebay that goes up to 5mhz, but it is pretty limited.