Frugal

Part of speech: adj

Source Sent. & Page #:
After having baby-sat for every frugal family in town, I eventually hit the mother lode. (Funny in Farsi, 123)

Context clues: logic, the sentence before shows that frugal means to be scanty or little expense

Definiton: costing little; inexpensive

Your Original Sentence: my mom tends to do her shopping at the 99cent store because of its frugal products.