I started building up my position at the end of 2022 at around €450 per share. When I posted the purchase here at the time, the general opinion was that Costco was far too expensive. I then filled my position up to a price of around €540. I am now up over 100% including dividends.
However, I wouldn't buy any more at the moment. On the one hand because the position is already my second largest in the portfolio anyway and on the other hand because I expect that it won't simply continue like this now, as we have already reached a very "sporty" valuation.