Hmmm. I am very skeptical we had the same headphone. Very V shaped (almost too much for a studio monitor). Did you ever amp them? If what I’m hearing is no bass or flat you’re gonna have a hard time finding something to satisfy you imo. Especially if you don’t want to shell out more than your budget.
I’ve used MDR 7506s off and on for ~20 years, and they still get head time with the ridiculous cans I have (Eikons, Clears, Hexv2, Elegias, PM-50s). There’s good reason for that. Don’t get me wrong, they have their problems, but I would never describe these as flat or lifeless. Slightly hollow mids sure, but that’s what you trade for the extension, detail, and dynamics for the price.
I don’t EQ things. If they don’t sound good out of the box, the manufacturer fucked up and you shouldn’t buy them 
But yea, tldr, if you don’t think these are bassy enough when amped then I’m not sure what to recommend that isn’t overly expensive.