In 1980, $82 (double occupancy; almost $250 in today’s money) would buy you a ride on the Coast Starlight from Los Angeles or San Francisco (via bus to Oakland) to San Luis Obispo, an afternoon tour of Mission San Luis Obispo, overnight lodging at San Simeon Lodge, a morning tour of Hearst Castle, and return trip by the Coast Starlight. Meals not included, but there were “many restaurants specializing in seafood.”
The Coast Starlight‘s schedule was convenient for such a trip provided you agreed that a single morning was enough time to visit Hearst Castle. The southbound train left San Luis Obispo at 2:15 pm while the northbound train left at 2:40 pm. If you wanted more time, an extra night at San Simeon Lodge was $36 (double occupancy; $105 today).