It is better to keep it as a souvenir, and there is no future if you sell it.

Because, the signature thing, the real person signed it for himself, and it is still interesting to leave memories.

If you buy it with money, it will be boring.

And when you sell it, how can you prove that it is signed by infi himself, not a fake? Hmm. How interesting

So I suggest you don't sell it, keep it for yourself.