David's bridal wedding dress

I have a David's bridal dress, originally paid about $600 in August, wore it for less than an hour. I haven't had it dry cleaned, it has a couple of spots (pictured) and the bottom could use cleaned but it isn't noticable. there is a couple of beads falling off (pictured). it is a 2 piece, the top is a size 10 and bottom is size 12, it was altered. I got the straps tightened and the front hemmed maybe 4 inches. if it helps, I am 5ft 1in and 155 lbs when I wore it. I am asking $450 but am open to reasonable offers.