Plan a camera gear purchase budget.
Camera bodies date quickly while good lenses outlive several of them, which is why the lens allocation is highlighted here rather than the body. Splitting a fixed budget into body, glass and accessories — and leaving a reserve for the cards, filters and repairs you forgot — keeps a kit balanced. If the shares you enter exceed 100% they are scaled proportionally rather than overspending the budget.
Gear budget split
Lens budget = total budget x lens share/100 (shares scaled down proportionally if they exceed 100%); reserve = budget - body - lens - accessories
Glass generally holds value and image quality longer than a body, so a lens-heavy split is the conventional advice for a first serious kit.
Memory cards, spare batteries, a bag and the occasional repair are not optional, and paying for them out of the body allocation is how kits end up unusable.
They are scaled back proportionally, so the plan stays inside the budget you entered rather than quietly exceeding it.