What are you using to establish the evaluation? Part of it is there were probably a lot more Gearboxes sold then the Next Level. Sites like NADA and KBB are not all that accurate, but they are a starting point. I feel like the NL was probably better built, but both have been orphaned at this point by their manufacturers.
Two Wire Fox Terriers; Sarge & Sully
2007 Winnebago Sightseer 35J
2020 Jeep Gladiator Rubicon