Biktrix doesn't charge tax for US sales.
Also the Eagle frame is built in California. So it depends on what you're after.
You're also comparing wrong bikes. If you were just after battery and range with Ultra motor, check this out:
ORDER AT BIKTRIX.COM. eBike with 1500W mid-drive motor & 2002Wh battery. Up to 35mph & 150 mi range. | Check out 'Biktrix Juggernaut HD Duo: Ultimate Range E-Bike' on Indiegogo.
www.indiegogo.com
52V 39Ah battery ebike starting at $2099 (albeit for a hub motor bike), $2299 for a bbs02 and goes up from there.