Hacker help: Ikea Besta with lock?

Photo: IKEA.com

Materials: Ikea Besta with Galant style combination lock

Description: Hello all, I am looking to purchasing a unit to use as a filing cabinet for my home office.

I need to put in a lock, the Galant system looks great, but the price tag is triple of Besta.

Does anyone have any suggestions, or previous hacks where they implemented the combination lock (Galant syle) into Besta cabinets?

Thanks!

~ Maria