"je'meH tetlh vIghertaH."
Translation:I am compiling a shopping list.
That's right: "a list for buying". Though it is also possible to interpret this as, "For the purpose of buying, I am compiling a list." It's up to you whether you want to interpret the je'meH as applying to the noun immediately following it or to the verb of the OVS following it. Though to be fully grammatical, if you are applying the -meH clause to the verb, you should probably have a matching prefix on it.