Based on the data provided, we can observe that the coin in question has had an average auction price of 134.8 euros in previous auctions. Additionally, the condition of this coin has been described as '80 (VF+)'.

Considering that the condition is good but not excellent, and that the average auction price has been 134.8 euros, we could estimate a maximum purchase price around 150-160 euros. This is because the condition is an important factor in the value of a coin, and although it has fetched good prices in previous auctions, it is important not to exceed too much in the purchase estimation.

Therefore, an estimated maximum purchase price for this coin in the next auction could be around 150-160 euros.