It is most reliable on measurable, high-contrast things: centering ratios, edge whitening on dark borders, corner rounding and large surface damage
While the most recent $600 sale hasn't been replicated yet, this card's price continues to trend upward as it becomes more difficult to find this card
Both Steven Stone and Metagross are highly popular characters, and as a result, the card is garnering significant attention from fans and collectors alike, leading to a high market price
Therefore, obtaining such cards might offer decent returns, especially if their value continues to appreciate
Until next time, Trainers
If the consolidation of the grading market under one corporate umbrella concerns you, CGC (and TAG) are your alternatives