There are several reasons why it is better to wait until you have enough money before buying something. Many of these reasons have been evidenced in the wake of late 2008's economic disaster and the phenomenon known as Credit Crunch. This is not to say, however, that waiting until you have enough money before buying something will always be desirable, or even possible.
The first and most obvious reason as to why it is better to wait until you have enough money before buying something is that the purchase will almost certainly prove cheaper in the long term. If you apply for a loan to buy something or buy it on a credit card and pay it off over a period of time as opposed to clearing the balance immediately it falls due, interest will be charged on the amount borrowed or spent. Particularly in the case of credit cards, this interest can amount to quite a substantial amount of money which many people may not realise at the time. The one exception to this rule is of course where an understanding parent or other family member is prepared to fund the purchase on an interest free basis!
The second reason why it is better to wait until you have enough money before buying something follows on logically from the first. When you get used to applying for credit and even relying upon it to make purchases, the habit can become quite literally addictive. Before you know it, your debts can have spiralled out of all control and you are essentially repaying only the interest every month, with the capital scarcely being reduced at all. The number of people who have found themselves in serious financial difficulties in this way would be sure to make many others think twice about ever applying for credit again.
On the other side of the coin, it is not always possible to wait until you have enough money before buying something. The most obvious instance where this would apply would be when taking out a mortgage to purchase a house. If you were to wait until you had enough money to buy a house outright, there is a very real possibility that you would never be able to afford to buy one at all.
Although it is wherever possible better to wait until you have enough money before buying something, a sensible attitude towards credit - whether secured or unsecured - can allow a careful balance to be struck and let you lead the life you want to lead, when you want to lead it.