According to the data on Narrative HQ, there are 979 active niches at the time of writing and about 354 niche owners.
Also, 3398 niches are already approved. Comparing this with the active niches, we should note that there are challenges somewhere.
Here are my suggestions:
1) the people that created the active niches that has no bidding at all yet approved should be contacted to know if there is a challenge in payment. For someone to suggest a niche, it means that they believe that such a niche will trend.
2) if this is not already present, the bidding amount should not be opened to the public until the person that suggested it fails to pay the fee at a given time window of like 2 weeks. This will ensure that others are not profiting from someone else research and idea.
3) a standard value in USD should be made for niches since some might not have the financial strength to win their niche. This will ensure that before anyone suggest for a niche, that the cash is there.
4) Discount should be offered to regular bid buyers since we understand that they also earn from contents on their niche.