Auction price of Schuco Examinico

Today I will present a part of my work about the auction price of old toy precisely about Schuco Examinico (see picture below). The data come from an online auction website that made 4 auction by year ( March, June, September and December) between 2014 and 2021.

I group by the month for see when there is more sales and when it is better to sell or buy. The line charts below show the number of sales ( in blue) and the average selling price (in red) per month.

As we can see, for Schuco the curve of the number of sales and the price of sale are opposite, the better way is to sell in September and buy in

December.