IPA: /ˌɪnɪkˈspɛnsɪvli/
KK: /ɪnɪkˈspɛnsɪvli/
In a way that does not cost a lot of money; cheaply.
She bought the dress inexpensively at the clearance sale.
Inexpensively → It is formed from "in-" (meaning not) and "expensive" (from Latin "expensivus", meaning costly or requiring expenditure). The word "inexpensively" means not costly or requiring little expenditure.
Think of 'not' ('in-') being added to 'costly' ('expensive') — that's why inexpensively means something that doesn't cost much.