Russia 1997 Extremely rare stamp from the St. Petersburg post office vending machine

In December 1997, an experimental automated postal kiosk was installed for a very brief period at the St. Petersburg main post office. It allowed customers to purchase postage stamps for their mail, with payment made in cash. A mandatory condition was that the stamps had to be used on the same day they were purchased. If the trial proved successful, there were plans to roll out similar kiosks at post offices nationwide. Following the currency redenomination on January 1, 1998, the experiment was suspended, as the machines would have required recalibration for the new ruble and kopeck denominations. However, this was never carried out. Unused stamps from the St. Petersburg kiosk are extremely rare, while cancelled specimens have an estimated value of around 50 euros, regardless of their face value