Short answers, pulled from the story.
Winners received an olive wreath made from a branch of the wild-olive tree that grew at Olympia. Theophrastus wrote about this wild-olive in his Enquiry into Plants and Pausanias described how Heracles introduced it as a prize for the running race to honour Zeus.
Gold medals were not awarded at the inaugural 1896 Summer Olympics in Athens, Greece where winners received silver medals and olive branches instead. The custom of awarding gold, silver, and bronze medals for the top three places dates from the 1904 Summer Olympics in St. Louis, Missouri.
At the 2020 Summer Olympics held in 2021 in Tokyo, Japan, the gold medal was worth about $800 while the silver medal was worth $460. Third place medals in 2010 had a metal value of about US$3 but increased to approximately $5 by the time of the Tokyo games due to material composition changes.
The first Olympic medals in 1896 were designed by French sculptor Jules-Clément Chaplain who depicted Zeus holding Nike on the obverse and the Acropolis on the reverse. The Paris Mint made these medals for both the 1896 and 1900 Olympic Games before Giuseppe Cassioli's Trionfo design won a competition launched by the International Olympic Committee in 1923.
Designs for the Winter Games medals are generally larger, thicker, and heavier than those for the Summer Games with square shapes or irregular circles appearing in events like Sapporo 1972 and Salt Lake City 2002. Glass appeared in 1992, sparagmite in 1994, and lacquer in 1998 as hosts included different materials while the inaugural 1924 Winter Olympics medal did not even feature the Olympic rings.