Setting a Budget
There is no rule about months of salary. Decide a figure that suits your means, then learn which of the four Cs to spend it on and which to compromise.

How do you decide on the budget?
In our view, the purchase of the diamond and the ring should be matched to a person's financial means.
There is a very wide selection of diamond rings at different prices, so you can buy a diamond ring at a low price, a moderate one, or with the sky as the limit.
The material of the ring naturally affects the price too - 14K gold is cheaper than 18K gold, and platinum is more expensive than the latter.
In the United States it is customary to say that you should invest the equivalent of one month's salary, or two months' salary (net), in an engagement ring.
But of course this is an individual decision, and it should be matched to your own needs and financial means.
Generally speaking, in Israel the average diamond size for engagement rings ranges around half a carat to 1 carat, and the price is of course determined by the diamond's quality (color, clarity and so on…)
It is important to define your budget and understand your needs, and of course you can consult experts in the field to look for the best options for your taste and your budget.
Where you buy has a real effect on what a given budget will get you. Because diamonds are priced per carat and quality is directly comparable once a stone is certified, many buyers stretch a budget further by purchasing closer to the source - directly from a manufacturer or established supplier rather than through several intermediaries. That can reduce added markups, widen the choice at any price point, and make pricing more transparent when you weigh size against quality. A direct supplier such as Israel Diamonds, for example, lets you compare certified loose diamonds (opens in new tab) by grade and price and set them in an engagement ring (opens in new tab) to suit your budget.
Remember! You need to find the balance between budget and quality!!
The ring and the diamond should suit you, and should not take you beyond your financial budget!