So you need a ql 100 HD to break even. A fully implanted Solitus MP or Trader with maxed stats at lvl 200 can get 809 (probably 830 or so if you go nuts with equipment and buffs). So what ql can you end up equiping? QL 130? That's 30 ql's above Dovve's explained minimum requirements. That's not a huge increase in damage but if Dovve's numbers are right you will do more damage. Yeah it's a huge IP strain but every person I talk to over lvl 170 has IP coming out of their ears.
You will do more damage with multi wield. Yes it's expensive, but it's not "broken".