The Latias & Latios GX Alt Art card, released in 2019, is one of the pieces collectors track closely. Its current range sits between $100 and $300, averaging around $200. The 170/181 number and the original print run remain key factors when authenticating a copy.
Real value hinges on condition: a Near Mint copy or a PSA 9/10 grade trades well above a played example. Before buying or selling, always compare recent listings on eBay, Cardmarket and TCGplayer, and stay wary of reprints. PSA or CGC grading can pay off once a card clears a certain value; weigh the certification cost against the expected upside.
Over the long run, iconic cards in strong condition ride out market corrections far better than purely speculative picks. Keep your copies away from light and humidity, in a sleeve and top loader, to protect their value.