Hmmm. Over the years, I've had a variety of funky pricing issues with Hertz on one-ways, but none related to my Gold number.

Just out of curiosity, what is that EWR-MCO rental costing you? Only reason I ask is that in the past 10 years or so I've probably done a dozen one-ways and never found Hertz to be even close to the lowest-cost option. I'm usually willing to pay a little "Hertz premium", but sometimes we're talking 100-200% higher, and I'm not willing to pay that much.

Most recent case - a standard SUV, one-way MSP-MCI, was $77 all in with National. Hertz would have been $220.

So if cost is enough of a concern to cause you to use multiple member IDs, it might also be worth it to look at other agencies. Among the major brands, I've found National and Alamo frequently have the best one-way rates. (Query them separately - even though they are owned by the same company, they frequently will have very different rates on the exact same car depending on whether you queried via Nationalcar.com or Alamo.com.)