My latest opinion is that there is not much a digital synth can't do that a software synth can do just as well. Its all just processors and 1's and 0's. However digital is never going to replace analogue....
Options in your price range:
-MFB Synth 2 (analog)
-Future Retro Revolution (out soon! - analog)
Or to get the price down, go to ebay and get a deal on a $1000+ syth for half the price.
A prime analog pick is:
-ATC-1x (analog)
If you did want to go digial then you can ebay the original version of the Nord Modular for a great price. Its a great digital sound design unit. No software synth is as nice and great for techno.