Buy Star Map 〈Tested & Working〉

"I want to buy a star map for my anniversary".

The proper article depends on whether you are referring to a generic item or a specific, already-identified map: buy star map

(Definite Article): Use "the" if you are referring to a specific map you’ve already discussed, such as one customized for a certain date or a particular brand. Quick Reference "I want to buy a star map for my anniversary"