I used to try dealing in them, but it's extremely rare to get near-complete boxes sold, because people prefer to try and fill their own boxes that they've worked on, on and off, over the years instead... As a consequence single gears sell, but not boxes.
As yours is as full as anyone without Wanderer can reasonably get, it may be desirable for someone who hasn't got one at all. However gears are now exceptionally easy to get, and that includes those marked as "Rare"; they all drop at the same rate from Sutek, both new and old, common and rare; there's no actual weighting to them any more, and you can get a gear every 2 minutes once you've got the quest memorized. So really you're charging for weeding out the duplicates and the time invested in grinding Sutek for the ones to fill a single box to drop.
As a rough guideline, the basic price should be this;
350k to 500k to buy a box itself from a Heritage Token.
Per gear; I used to sell the duplicates for 5k each in Luna. Newer ones tend to shift quicker because there's more boxes needing those, but they tended to sit around for a week or two even at that price. 75 x 5k is 375k, so you're looking at those prices of a box around 1m.
Charge 20k for each gear and you'd only get up to 2m, but most players will start going and getting their own gears at that price. Sorry to say, but Dawn's boxes simply aren't worth much, which is why I have given up trying to fill the last 5 boxes I was working on myself.
If it included Wanderer however... that would be a different matter. I bought my gear for 6m a year back, and one went recently for around 5m that I saw. As a complete box you could probably get around 10m then. The sites that shall not be named are selling them illegally for $20 I can see, which would be about 20m, but I'd be surprised if you could get anywhere near that in game gold.