Literally nobody would be unhappy if it didn't cost any nanites at all. In fact I'll predict right now that removing the nanite cost will be one of the first support questions. Imposing a game resource cost for an action that has no gameplay effect is a very strange choice.
I'd be unhappy, because it takes something away from collecting rapiers. Giving everyone the choice to immediately choose whichever one they want for free takes away some of the fun of searching for the rapier colour you really want or finding all of them.
There's value in rarity and in finding something rare that you want. This is also why people are willing to pay money for "legendary loot boxes" on the off chance of finding a rare cosmetic that they like. Getting excited when finding something rare like that is a core part of human nature and I like that you can't simply toggle the rapier you want.
But I don't think it will be a support question at all since it's already been accounted for. Check the first post for the new beta which has 2 versions, a hack version which is what you see in the video, and a version where right clicking simply cycles through the available colours for free.
The free version is there for those who want it. I recommend the hack version, as it keeps the rarer colours (like the black rapier) special, but to each their own. I'm not going to judge anyone for using either version, and nobody is "ruining" their experience by using one version over the other. I'm more than happy to provide multiple versions. It's
not exactly difficult to do and largely handles itself automatically.
I guess we can see how many downloads each version gets, but I think you'd be surprised how many people will want to have that extra level of resource investment.
Nobody is clamoring for a "Freely unlock all GamePig games" mod either, despite the hack for it being very hard and requiring significantly more resources than the rapiers in this mod. People are more than happy to pay for non-gameplay rewards that add flavour or enjoyment to a playthrough without being numerically advantageous. All the lore-building non-gameplay fluff that's interactive and part of the world is the essence of what makes these sorts of games so immersive for so many people.