The 13th edition is still perfectly valid. Calculus has not changed in 300 years. Unless your professor assigns homework directly from the 14th edition, the 13th edition is an intelligent, cost-effective choice.
Sometimes, publishers offer digital versions of their textbooks. Check the official website of Pearson, the publisher of Thomas' Calculus, for availability. Thomas Calculo Una Variable 13 Edicion Pdf
: Focuses on a modern introduction to calculus, prioritizing an integral understanding of core concepts over rote memorization. The 13th edition is still perfectly valid