Much depends on which cryptocurrency you are buying, how much you want and where you are.
As long as you are in a country that has not banned the purchase of digital currencies (attitudes vary worldwide), you will probably be able to use an encrypted exchange. There are dozens of retail outlets to choose from and each supports various legal currencies, which means you can get your hands on Bitcoin, Ethereum and others regardless of whether you use US dollars, euros, pounds or Japanese yen as a payment method.
Many of these centralized exchanges claim that they make buying cryptocurrencies as easy as spreading on a pair of socks on Amazon. Although this is true to some extent, there are some legal requirements to keep in mind. Depending on the payment method used and the amount of encryption you are purchasing, you need a photo ID to verify your identity. Decentralized trade is another option, with smart contracts and atomic swaps used to facilitate peer-to-peer transfers and eliminate the need for an intermediary.
It is also essential to check whether the transaction fees of an exchange are higher than the market average and to verify that an organization is reliable. Paying too much to acquire encryption is one thing, but losing funds for a devastating hack is another. Even big brands like Monte. Goxes have fallen victim to cyberattacks in the past, so keep in mind that convenience does not necessarily take the risk.