Actually, there is nothing to regret IMHO.
If you are going to use winesearcher to make comparative decisions, it is important to dig a little deeper than just looking at the lowest price.
For example, the $432 bottle of 2021 Margaux on winesearcher is a clearance sale item at a small store in Pennsylvania that only ships within Pennsylvania. This store also has the lowest Lafite price per winesearcher. That is great if you live in Pennsylvania and happen to catch the sale (I have no idea how long the sale has been active or will continue), but it is not a great way to make a buying decision of those two things do not apply.
You also have to consider the fact that, as in this case, you would be buying from multiple stores. At current rates it is very common for even a single bottle to cost up to $40 to ship ground. Not at every store, but certainly at many. And so shipping and taxes can add up pretty quick.
You also need to remove auctions and pre-arrivals from your search. Auctions list reserves or low estimates, and pre-arrivals are often subject to tariffs these days plus potentially long waits. Since you can buy these bottles on winebid now, your winesearcher search should just consider what is in hand and available from other retailers. Many of us have learned the hard way that when a pre-arrival is cheap on winesearcher, it often gets snapped up quickly but the pre-arrival offerings can last for days since many retailers are quoting from the same set of European sellers. It is not uncommon for 5, 10 or more prearrival offerings on winesearcher to be for the same European wine/parcel of bottles.
Finally, once you are looking only at retail offerings, look for that price range- on something like a recent first growth it will be a very tight range- from a handful of major national retailers that are accustomed to shipping and who price competitively. The rough average or midpoint on that range is your reasonable comparison.
When I apply that methodology to your situation I come up with about $575 for Lafite and $500 each for the other 3. That is $2,075 plus tax and shipping which is going to be right about the $2,300 all in you are looking to have spent. Plus you got it all at once and just have to arrange shipping once- your time is valuable too.
So in my book you made a very good deal. I bought my favored first growths in 2019, 2020, 2023 and 2024. 2022 is not a style that I like. 2021 I do like but I thought they were a bit expensive. Prices may come down, but when considering the current state of supply- I do not expect it. And so I am looking at doing something much like what you did- find a good and convenient way to buy a handful of bottles to allow for an eventual tasting and evaluation and have that rare knowledge that only comes from giving every vintage a chance.