It’s H2O. Buy Evian and drink it. Cheaper and better for you.

One should never "buy" holy water as it is a sacramental in the Catholic church, is blessed by a priest, and is freely available at no charge to the faithful. As for Lourdes water, while it is not blessed by a priest, the faithful see it as a conduit through which God's miraculous graces sometimes flow. It just doesn't seem right to pay for it, not to mention you can never be sure it is actually Lourdes water when you purchase it. Nonetheless, I have gotten the real deal from Our Lady of Lourdes Hospitality North American Volunteers. They do not charge for the water but accept donations if you'd like to offer something toward shipping or their organization. At the time, I wasn't able to make a contribution. I received 2 bottles for free. Here's their link: https://lourdesvolunteers.org/request-lourdes-water/

OK, I won't buy it. Thank you for your great comments.
-- OP

As a Protestant, OP, I get where you are coming from. My husband and children are Catholic, and I find relics and holy water more fascinating than they do.

Do not do this, though. It is sacrilegious on one level, like taking Holy Communion in the Catholic Church as a non-Catholic.

There is no magic in these things. It is simply a reflection of your faith and connection to your religion. If you do not have that, it won’t “work.”

I'm French. No one buys Lourdes water for the purposes you describe. It's a bit offensive, to be honest.

You can’t actually “buy” Lourdes water. It is loosely what is called a “sacramental” and can’t be sold. You are buying the container.

Lourdes water has been attributed with miraculous properties associated with the appearance there of Mary, the mother of Jesus, according to (non-mandatory) Catholic belief. It is not technically Holy Water unless it has been separately blessed in addition to coming from the spring at Lourdes. I’ve used it as such, however, and not felt that it was inappropriate.

What you propose, as a non-believer is more akin to magic or superstition. It would be inappropriate of you to misuse Lourdes water in this way.

If you’d like to know more about Lourdes and the associated Catholic devotions there’s a ton of information on the web.

Good fortune? Lol, no. That's not really what it is about. I'd avoid the cultural appropriation inherent in buying it and using it if you don't even know what it is.

I was visiting the gift shop at the Basilica of the National Shrine of the Immaculate Conception in D.C. recently and saw a basket of small bottles (about 1 fluid ounce) of Lourdes water. The cost is $8. Should I buy one and do something with it, like sprinkle it in my home? Will it bring me good fortune? I'm not Catholic nor particularly religious but I do believe in a creator -- maybe I'd be called a deist. I'll visit again at some point and wonder if I should buy some of the water next time. Thanks for your advice.