Given that the coin has a condition of 30 (BC+), which indicates that it is in quite low condition, and considering that there have been no previous auctions or sales of this reference, the starting price of 650 euros seems a bit high for its state of preservation.

In general, coins in lower conditions tend to have final prices significantly lower than their starting prices, especially if there is no sales history to support the price.

Since there is no historical data for this coin and considering its condition, an estimated maximum purchase price could be in the range of 200 to 300 euros, depending on the interest of collectors and demand at the auction. This would allow potential buyers to take into account the risk associated with purchasing a coin in low condition.