Use the weight test (genuine cards weigh ~3.4g), light test (hold to bright light genuine cards show a dark blue/black core layer), and magnification (genuine cards show clean rosette dot patterns)
For any valuable card, professional grading from PSA or CGC is the gold standard
manga and the Japanese version of the anime, the card text of the Egyptian Gods (except the hieratic text of "The Sun Dragon Ra" ("The Winged Dragon of Ra" in the anime)) is written in English, likely due to the one-of-a-kind cards being created by Pegasus, who is from the United States of America
For example, Counterspell from Ice Age is $1.49 if they buy it from the store, and SCG buys them for around $0.10/each
$15 is a magic number
If you choose not to perform either of these two actions, you can pass this phase and go to the Main Phase