Because they are extremely tricky¹ to make and many of their ingredients can be expensive and/or difficult to source.

因为它们很难制作，很多原料都很贵或者不易获取。

Macaron shells are made by folding almond flour (or some other nut flour) and confectioners sugar into a meringue (sugar and egg whites). Sounds easy enough, but it has to be done just right. The ratio of sugar-to-almond flour-to-egg has to be very precise - you have to weigh your ingredients to the gram; you can't do it by volume. I suppose you could but it could easily mess up your batch².

马卡龙的壳是一层杏仁面粉（或其他一些坚果面粉，糖和调和蛋白制成。听起来简单极了，但是要做到恰到好处很不容易。糖、杏仁面粉、鸡蛋的比例都必须非常精确。需要将原料按克称量；另外，你不能按体积来计算。我觉得其实你可以按体积来算，但是这样很可能会搞砸的。

Assuming you've even measured the ingredients properly, you need to fold it correctly. Under-mix and they'll be stiff. Over-mix and they'll be goo. You have to pipe the shells to be uniform in size, rest them so they can lose their peaks and watch them like a hawk³ for as long as they're in the oven. If anything anywhere in the process goes wrong, the entire batch can be lost. And macarons are as much about looks and style as taste; a cookie that tastes good but is burnt, missing its foot or cracked will not cut it.

即使你恰当地称量了材料，你还必须正确地把它们卷起来。不充分混合他们会变硬。过度混合它们又会太软。你必须把这些壳都卷成统一的尺寸，把它们放在一边，让它们变得柔软，从放进烤箱的开始一定要一直看着它们。如果步骤中的任何一处出了差错，整个一批就全部白费了。一个小曲奇味道很好但是烤焦了、少了一个角或者破了是不会有什么影响的。

The fillings don't have to be that difficult. I've used buttercream, ganache and candied fruit, among others. It's the shells that pose the difficulty, and unless you want a plain shell, you'll need to invest in good-quality vanilla⁴, edible⁵ flowers, cocoa, flavor compounds, spices and dye. Most of that ain't cheap, and neither is almond flour, unless you buy it in bulk⁶.

內馅没有那么难做。我用了奶油乳酪、巧克力酱和果脯等等。其实是壳使得制作难度提升，而且如果你不想让壳平平的，你就需要买很好的香草酱、可食用的花瓣、可可粉、混合调味剂、香辛料和染料。它们大都价格不菲，扁桃仁面粉也是，即使你批发，还是很贵。

In summation⁷, the comparatively high cost of macarons is a function of their difficulty to make; the time it takes to make them; and the cost of their ingredients, many of which are highly specialized⁸. Most people are also unwilling⁹ or unable to make them at home (they are not cupcakes and there is no boxed mix for them), so they're willing to pay more to get them from a bakery.

总的来说，马卡龙的高成本来源于它的制作难度、制作时间和原料价格，这其中的大部分都需要很专业才行。大部分人也不愿意在家制作它们（它们不是杯子蛋糕，也没有混合好、方便制作的原料包），所以人们愿意花更多的钱去面包店买马卡龙。