Me, too. Have lots of mags of Beaujolais and Muscadet, things like Thivin and Roilette and Pepiere that I’m happy to drink, but also happy to serve to about anybody. Just a few mags of more serious wines, usually because they were available at a good price – or in the case of 1995 Musar, because that’s the only way I could get the wine at all. Still have 3 mags of my original 6. In general, I very rarely buy more than one mag of anything, though.
I’m perplexed why anyone is perplexed. you take a baller wine and offer in magnum. It’s hard enough to get offered the 750.
I have a fair bit of wines in mags for thanksgiving and Xmas dinners, where that format shines. Mostly Chateauneuf du Pape and Beaujolais.
Wow, I just checked and I have 49 mags. That’s more than I thought. They can creep up on you.
There is less exposure to oxygen in magnum, so the fermentation can take a bit longer. Also some, like Cristal, actually reduce the amount of sugar added with the yeast for the secondary fermentation to take account for the differences in fermentation vessel, so the concentration of sugar and yeast is not the same.
That all being said, I wasn’t trying to imply that champagne from magnum is always better - just that it is always different because it undergoes secondary fermentation in different conditions.
2.25X would be my limit. As Robert said, magnums are nice for Holiday gatherings, and for birth-year/anniversary bottles. We don’t have anything larger than a magnum in our collection, mainly because of there are very few occasions where it would make sense to open one. I also seem to recall Robert Parker saying that the corks for any bottle that is 3L or more are made by hand, whereas 1.5L and under are machine made and less likely to have a problem? Not sure if I read that in a Wine Advocate or on the Squires BB.
Ed
Cost of goods is higher - smaller runs, higher label cost, higher bottling cost, higher bottle and cork cost.
But the main game is scarcity demand.
I think the typical EP pricing is +£5 for magnums (6x75 cl vs 3x150cl) based on my inbox history.
That I think is definitely worth considering the magnums - I personally prefer bottles as they’re a bit more drinkable than having racks upon racks of magnums, but magnums and higher clearly are good investments longer term
I can remember back in the early to mid 2000’s when here in New Zealand and to a lesser degree in Australia it was very rare to find local magnums, though EP Bordeaux mags and French mags in general were around. There were producers asking three and a half times the price of a 750ml and I guess they played the market forces game where assuming that they sold them, then the price was a fair one? That sort of pricing completely put me off though. Soon, some lower end Australian producers started doing a LOT of magnums as promo offerings (‘buy a dozen btls and get a free magnum etc’) and it seemed to make magnums much more normal and commonplace with prices becoming more sensible.
I peaked at about six dozen large format bottles in the cellar, but that has slowly whittled back to a whisker under 40 as I take them out just a whisker faster than I buy them…mind you neither consumption nor purchasing is significant in a given year.
A couple of posts her mention that a mags have the ability to age longer, which makes sense.
The term I’ve heard used in the past to explain the higher cost, is the mags age more, “Gracefully”, whatever that means.
Has anyone ever done a side by side comparison of wines being aged the same way, for say 10 years, one being a mag, one being a 750, and blind tasting? Would be really interesting to see that difference.
And yeah, Scarecrow markup is insane, especially for the 3L. Clearly, you are paying for the exclusivity, and bragging rights - $5000k for a 3L = over 3x markup.
Yeah I heard that too. Then I opened a 3L and found out that it has the same normally processed machine made cork. It’s > 3L that has the hand cut corks.
I dont know what the aging rate is driven by, though I suspect it’s probably cork surface area divided by volume of wine total (or some function of that). If you assume a magnum is ‘half’ the rate, you’d need to compare a 2010 vintage of something in bottle aged for 10 years against the 2010 vintage of that aged in magnum for 20 years, which clearly isnt functionally possible
If someone is keen for the science and willing to donate a bottle of 1998 hermitage la chapelle, I’ll pop my magnum and give you my thoughts 
from what I Read, though, the bottles are largely over the hill, last time I had a magnum it was amazing