Arbor chips? Do you mean wood chips? Any place that sells bark would also likely have them. We always use Sawdust Supply Co. on 7th Ave. in Georgetown. They are great!
I assume you mean arborist chips that you get for free? Those are not available at a given location, but you can get on a list for a free drop at the Chip Drop website. Unfortunately, you have to take a full load (usually up to ten yards) and there is no scheduling or notice involved. Otherwise, Sawdust Supply is probably the best source and a yard or two will fit in a pickup. Guessing it would cost around $50.
If you don’t need them immediately, you can call arborists and tree trimming companies. Sometimes they’ll bring their chips to you if they’re working in the area. It saves them dump fees.