Thanks for being honest there with the prices. All I was going to suggest was for that money, you could get a 3port and tune from @TME_Steve and the car would be exponentially better.Kyp had a couple in stock so bought it for $390 and $160 to install.
Did a search the price i got on the unit was good.
I note that you're in Perth and its not a common place for Steve to travel, he been there in the past. Something to consider for next upgrade