To estimate a maximum purchase price for the coin in question, we can analyze the provided data, including the starting price, current condition, and previous auction hammer prices.

1. Starting price: 2500 euros.
2. Current condition: 80 (MBC+).
3. Average hammer price in the past: 5030.1 euros.
4. Previous hammer prices:
- 1301 euros (condition 85)
- 5700 euros (condition 95)
- 9500 euros (no condition data)
- 7500 euros (no condition data)
- 2700 euros (condition 95)
- 2300 euros (no condition data)
- 9000 euros (condition 95)
- 5100 euros (condition 95)
- 5400 euros (condition 85)
- 1800 euros (condition 85)

The current condition of the coin (80) is lower than that of many coins that have been sold in the past, which could influence the hammer price. However, the average hammer price of 5030.1 euros suggests that there is significant interest in this coin.

Since condition is an important factor and considering that most coins with a condition above 85 have reached higher hammer prices, we can estimate a maximum purchase price that takes into account the current condition.

Estimated maximum purchase price:
- Based on the average hammer price (5030.1 euros) and adjusting for the condition (80), we could consider a discount of 20-30% due to the lower condition.
- This would lead us to a range of 3500 to 4000 euros as a reasonable maximum purchase price.

Therefore, an estimated maximum purchase price could be approximately 4000 euros.