Why not just get another GR02 BE? I haven't heard anything that sounds very similar to these but better - they are just bassier than the VSD1 and most of the other sets I recommend often these days, so I don't think there's anything more suitable for you in that price range. The ATH-CKM500 might be worth considering but its deep bass is not as prominent as that of the GR02.
Yes, that's what I'll probably end up doing, but I wanted to do my due diligence before I did that. What about some sets from Brainwavz/DUNU/Astrotec/VSD1S? Are there new VSDs launching soon in this price range? VSD 3/4/7/9, etc