Welcome to Narrative!
The start price is the equivalent of $75, in NRVE, at current market price. You can see current market price here. The amount of NRVE will go up and down due to market fluctuations, but it is always the equivalent of $75. Once a niche successfully passes through the approval process a niche can sit available for auction indefinitely, however once it has received the first bid the timer starts and the auction runs for 72 hours.