Hmm. When I log in I get the 4 woofers for 158 euro each. I might be getting a higher discount for having used them quite a few times by now168 Euro when buying 4 woofers - still good price
But 300 a piece is 1200 for 4 units, getting the ones from overseas is 800 bux so 400 bucks savingshttps://www.madisoundspeakerstore.com/sb-audience-pro-sound/sb-audience-rosso-18sw650-18-subwoofer/
This is the least expensive option from Madisound.