This year, zero!
Our house stands out in the neighborhood this time of year for its imitation of a black hole. And if you think your neighbor spends too much on the lighting, watch the "Decorating for Christmas" shows on HGTV.
As a lapsed Lutheran, my adolescent Christmas holidays were a crazed juggling between the religious stuff and the commercial stuff.
The "worst" Christmas came on a Friday. You had the Thursday night Christmas Eve service, preceeded by weeks of "last-minute" choir crisis rehearsals. (Hey, if you gotta be there you might as well be doing something.) Sometimes this was even timed to end at midnight, although driving home in Pittsburgh's winter weather was exciting enough during daylight. A few short hours later you had the Christmas morning service. (Luckily the sunrise version of this never caught on.) Next day was the "day after Christmas" service for reasons that I probably forgot soon after catechism. And the next day-- it's Sunday! Even the pastor was struggling for meaningful sermons.
The commercial side was even more hyperactive: Shopping. More shopping. Gift exchanges. Baking. Even more shopping. Visits to relatives you haven't cared enough about to visit since last year. Yet even more shopping & baking for their impending visit to your house. If I'd known then what a Myers-Briggs profile was I would've immediately understood what the holidays do to an overstimulated INTJ.
The reductio ad absurdum came when I reported to my Pearl Harbor submarine to find that I had "just missed" the holiday decoration competition. There were over a dozen submarines inport that year, all of them festooned with testosterone-drenched blinking lights and imaginative uses of raised periscopes. It's a good thing they were on shore power because Naval Reactors would have had to significantly adjust their overhaul budget for the nuclear fuel consumption. Our XO was seriously ticked off that a rival sub had won the competition "AGAIN!!". Later I learned that the rival's crew had spent the previous weekend working overtime to get the decorations in place. I can only imagine how they felt as they went back home that evening to decorate their family trees.
So in a hyper-reaction to those years of enforced corporate worship, crazed spending, and monuments to excess, our lighting budget has stayed below $50 (total) over the last 20 years. That bought an artificial tree (garage sale) with lights, tinsel, and colored glass balls. Ornaments have been provided by family gifts and kid's crafts.
Don't get me wrong-- I'm not a Scrooge and I enjoy a good gathering just about any time. But I don't see the need for going overboard on the religion & commercialism as if to make up for an entire year's worth of neglect to both categories.
One of my happiest holiday memories is taking the boards to Barbers Beach last Christmas for our kid to test out her new paddling gloves. There were dozens of families on the waves, all enjoying their presents and the time with each other. I never found that Christmas spirit in the churches or the shopping malls!