Privacy.com is also an amazing way to save money. I use them for any online payment where I cannot use Bitcoin. For any subscription or service I only want to use once or limit my spend to a specific $ amount - I use a one time card, and I cannot tell you how many times some forgotten subscription or bullshit charge comes around in 6 or 12 months and I'm saved by this service. So even privacy aside, its a good money saving/budgeting tool because you can control EXACTLY how much and when you spend and it cannot go a penny over.