Value of a NOS M400?

If I shouldn't be asking this here, mods, please delete.

I bought this pen about 18 or 19 years ago. I don't think its seen daylight more than two or three times. Certainly never been inked.
My interests have changed and I would like to sell it/trade it. But I don't know what its value may be.
I kind of recall the tortoise was a limited run.

If someone could suggest a fair value, then I believe I'll be able to list it for sale.

Thanks

https://imgur.com/8Axfvxd

https://imgur.com/XIi1DR6

https://imgur.com/PccKaWmAttachment 68436Attachment 68437Attachment 68435

The Ebay 'sold items' list gives a rough idea on value. Because Ebay takes a significant fee on all sold items, the ebay 'sold item price' minus 10% would be a correct selling price if the pen is sold via a non-commercial platform.
According to Ebay, the M400 Tortoise sells for at least $ 250. The pen being never inked with original box and paperwork included, and eventually also an original receipt, all add to that value.

www.ebay.com/itm/264874435472
www.ebay.com/itm/133955364429