Perhaps you already know this: The yen was introduced in the late 19th Century as a one-dollar coin, which was an internationally standard weight of silver. 100 sen were a yen, and 10 rin were a sen. As everywhere else, money was later debased and the currency units lost purchasing power as the state paid for things by printing and minting nominal money. Coins valued at less than one yen were demonetized in 1953.
It is especially problematic to compare purchasing power across long spans of time. But, using standard measures, a yen at the time of this story would said to be worth about 2900 yen now.
That makes thd bidding in this story seem absurd, but the mangaka probably knew very little about the price level and probably didn't expect many readers to know or to care.