When you find a Magical Pea Chia Pop sitting in your shop...

I'm going through my shop trying to put prices on items (I fill it faster than I can price) and find a Magical Pea Chia Pop. Put it in JN Items Database and it tells me it's worth 7m (or so).

Nice.

Any advice on how to price items like this? The other 3 on the TP say "NM offers" while JN has the value changing from 5m 2 years ago to 10m earlier this year.

I'd be happier selling for less to someone if I knew they were going to use it, but is there any way to do that or can re-sellers just say anything to get a discount?