Two worrying trends in our culture, spending too much on weddings and spending too much on elective cosmetic procedures, come together : AFTER the band was chosen and the napkins color-coordinated to match her shoes, Kacey Knauer, a bride-to-be, had another critical matter to address: her skin, and the skin of the nine women in her bridal party. So Ms. Knauer, the 35-year-old owner of TempTrends, a staffing agency in Manhattan, invited her nearest and dearest — including her mother and future mother-in-law — for a night out at the TriBeCa MedSpa, replete with mimosas and cupcakes. An aesthetician assessed each woman’s face and devised a treatment plan — a quick chemical peel, say, or an injection of a wrinkle-filler. Or maybe, for a bridesmaid with age spots , a series of Fraxel laser treatments over months, allowing for recovery time. When watching historical dramas like the recent John Adams , I'm constantly amazed at how modest and understated the weddings seem. For the sake of ...