When I was starting out I was given the tiny B3 as a gift. As soon as I realized I was hooked I acquired the Etherwave Standard and still play it from time to time. Then I decided to go back to Burns and ordered the Walnut B3 Pro. Eventually I sold that because I felt the notes in the low range were rather weak and it didn't sound much different than the B3 to me. A couple years later I found a good deal on the Etherwave Pro and to this day it is the goto instrument I play the most. After that I got a Subscope Voicematic B3 and still enjoy it. Next I found an antique Moog Melodia which was fun as a collector item but with limited playability. When the Claravox came out I ordered that but it was cancelled because of the production delay so I ordered a theremin from Charles Hobbs instead and love playing it as well.
Sorry to bore you with my theremin addiction story but in the final analysis I believe that you can't go wrong with the Etherwave Standard. They are becoming rare now but you can still get one on on Ebay for under $500 if you try. I think it's a solid instrument that you will not outgrow. A professional will make the EWS sound like a million bucks but a Claravox played by a beginner will sound like any other theremin out there notwithstanding fancy sound effects. Watch lots of Youtube videos and with your budget in mind decide what you visualize yourself playing for the next five years or so.
Good luck on your journey and if you win the lottery buy them all!
