I've been there myself. Sometimes the truth hurts but if you can imagine for a moment the pain of witnessing your wife doing you a favor by polishing the acrylic faceplate of the Electrocompaniet CD player (that a long lost Norwegian friend sent you) with a cheap, dry paper towel, pick up the Audio Note speakers you got at a garage sale and set them front-faced-down on the coffee table so she can dust/shop-vac underneath them, then set them back on the stands and shop-vac the dust off of the drivers and tweeters, spray the platter on that old SME20 you purchased at GoodWill with Armor-All getting it all nice and shiny again, putting tie wraps around all your cables to organize things a bit better, pulling those filthy, dusty, metal base GEC KT77 tubes from an estate sale on your amp and sticking them in the dish washer, etc.
Now... this "favor" would make most audiophiles freak out, but try explaining your freaked out behavior (why you aren't thrilled about what she's done for you) without attaching a dollar figure it. Impossible.
It seems best to be honest.