thats a tough one! the U's are "bottom-end" vowels and not considered premium letters, but it HAS 3 dang vowels! in comparison, i sold a similar 3 vowel name with K instead of D for under $200 about a month ago.... your name is in my opinion higher quality but, at current market, i think the $400 offer is very fair. Of course, you can hold onto it and most likely make more down the road, or take whatever the ROI is for you at $400 and reinvest in more/better names while they are still reasonable.
for what its worth..... SP