I want to buy all my cooking utensils in one go.

Literal

Cooking-utensils [object-を] in-one-lump buy-want.

一括して ('collectively, all together, in one batch') is a formal adverbial phrase — 一括 ('lump sum, batch') + して (て-form of する). 買いたい is the desiderative ~たい ('want to do').