For the specific range example you gave you could use an (else:) macro instead of an (else-if:) macro.
(if: $gold >= 7)[You have enough gold]\
(else:)[You need to find more gold]
When you need to check a variable against multiple ranges you can use a set of cascading (else-if:) macros like the following.
(if: $gold >= 15)[you can afford the 15 gold item]\
(else-if: $gold >= 10)[you can afford the 10 gold item]\
(else-if: $gold >= 5)[you can afford the 5 gold item]\
(else:)[you can't afford any item]
The above cascade works because the process of the set stops as soon as one of the conditional expressions evaluates to true.