You could buy used, or use a gift card for somewhere, and there's a cheaper, handheld-only version, but for the most part Nintendo consoles never go on sale.
make sure when you purchase you get the red box switch. It was recently revised and has a much better battery life.
The latest deals before the holiday included a $30 gift card to the retailer you purchased from but I believe those are all done.
Expanding on the rest of the responses, the consoles usually don't go on sale, but they often have "deals" that are the console bundled with games for the price of the console.