Several factors influence Neo Discovery card values: card condition (mint cards worth 3-5x more), rarity (holographic and rare cards command higher prices), first edition status, PSA/BGS grading scores, and market demand for specific Pokemon
The instant speed protection and proliferation make this a very loveable card
As for something else to keep you busy at the tabletop, don't miss the best board games
I am leaning Archfiend in general because being able to block and survive against Lovestruck or the Beast token when it is a 5/5 from stage 3 of Huntsman seems very valuable
Nevertheless, if you choose to do so, abilities that trigger "whenever you collect evidence", such as those of Surveillance Monitor and Evidence Examiner, will still trigger