To me this is a much more workable solution than the other common proposal (but that's not difficult as enforcing a maximum price that's below market value is a total non-solution).
More than that I think this is the best solution that I've thought of or been made aware of. Yes someone who's bought 3+ of the same ticket as an investment might be out a considerable amount of meseta but (a) they bought them as an investment in the first place and investments can collapse in value, and (b) had this system been in place since NGS launch as it should have been, they wouldn't have been able to do that so this situation is just as much the fault of delayed implementation and intentional exploitation as it is the system itself doing what it's meant to. Post-implementation this wouldn't be a problem.
And I say this as someone with a couple spare Start Dash Rappy stamps and Crawl Swim motions, having picked up some insane undercuts (my justification is someone's going to snatch those to resell, so me being that person isn't going to increase reselling that's going to happen anyway¹) and not having had the slots to sell them yet I'd lose out from the change too - but I'd be cool with that for the good of the economy.
Buying "mistakes" rarely happen, and they can be further protected by not letting someone buy an emote, motion or stamp ticket from a player shop if they've already registered it, or a layered wear or accessory ticket if they've already registered two. This would be quite effective protection because they're extremely unlikely to be sitting on an unsellable ticket - if they got an unsellable ticket previously it's because they bought it from the player shop because they wanted to use it and would have used it right after buying it. And if they have a sellable ticket (that they got from an AC scratch), they can just use the one they just bought and still sell the sellable one, no harm done.
Lastly I don't see how this would make AC scratchers hold onto their items any more than they might already do. Anyone who scratches with any regularity - and even anyone who plays for any length of time and only scratches exceptionally - knows that AC scratch items increase over time, so anyone doing the scratches is going to sit on them for a while if they have the capacity to anyway. It follows that most of the AC items being sold immediately is either due to having to due to storage space (which means they would sell fast anyway) or having so much meseta or ability to whale future AC scratches that they don't need to wait anyway.
¹ Oh and by the way, if you read that and thought "But what if you stopped someone buying it who would have used it for themselves?" then congratulations, you support this topic's idea.