Yes you should still have unsolds and I understand why you are doing it but you do not need to have as much or make the foundation of your suggestion unsolds.

Unsolds aren't a valid proof and shouldn't be the foundation of a suggestion. A handful of unsolds might be remaining unsold for reasons unrelated to the market- poor bumping, poor trader availability, recently editted prices, etc. Far better for lowering a range to a flat price is demonstrating that there are large quantities of willing seller at the bottom of the range.

I'm not saying there's an issue with this suggestion, your very thorough look at the Tyrantium Helmet has your bases fully covered. But structuring the suggestion to have the strong, bottom range sellers first and the much weaker supporting unsold proof at the bottom isn't a bad idea for future suggestions. :)