Smart light bulbs are a bit more expensive than your regular bulbs, and that's because it needs a bit more hardware (like Wi-Fi connectivity). And right now the TP-Link Smart LED Light Bulbs are on sale for 43% off of their regular price. Now only their 50W white bulb is on sale for $19.99, while others are at their respective regular prices.
TP-Link's light bulbs here are pretty interesting for a number of reasons. The most interesting is the fact that they work with the app on your smartphone or tablet without needing a bridge, like the Philips Hue light bulbs need. Which means you can simply buy one light bulb and get started in changing over your home to having smart light bulbs. The other reason is the fact that these work with Alexa. Now what that means is that if you own an Echo or Amazon Tap, you can use your voice to control your lights. Which is pretty incredible in 2017. You can just say "Alexa, turn on the lights downstairs" and within a few seconds the lights will come on.
It's unclear how long this price will be available on these smart LED light bulbs, so you'll want to pick these up before the price rises back to its regular price. You can grab them from the link below, and if you're an Amazon Prime user, you can get them as soon as tomorrow. If not, you can sign up for a free 30-day trial of Prime, and cancel after your 30 days.