In my opinion I think this all depends on what's most valuable to you in terms of usage, time and resources. You have options, and typically, you can pick two out of these 3 to find what works for you: Fast, Cheap, and Easy.

I think there are 3 ways in getting equipment for small businesses:

1. Big warehouse stores: Costco, Sams
2. Office supply Big Box Retailers, Office Depot, Staples, Office Max, Wal-Mart, and local supply stores
3. Online sales, Amazon and others

I'd break it out into two types of small businesses:

We go through serious supplies: (Easy, Fast)

You can get discounts with the big box retailers having a small business account, and they do delivery. This varies based on the amount of products you go through a month, but typically a local supplies retailer will match the big boys and have much much better customer service. I typically look local first, big box second.

We go through occasional supplies, and use the printer moderately: (Cheap, Easy)

I think the most underrated small business supplies is by using Amazon. Look into getting an Amazon prime account for 79 dollars for a year. This will get you free 2day shipping on about 70-80% on everything that Amazon ships, including business supplies like REAMS of paper. It's by far the best deal on the internet if you utilize it correctly. It's really everything they ship, and since they do distribution and drop-shipping for many other companies, those items don't typically get facilitated through their prime program. This alleviates having to use sweat equity to go out to the stores yourself, and rely on UPS/Fedex to do the delivery for you.

Warehouse Stores (Cheap, Fast) Moderately priced, all bulk items. It the one you have the most control over, where you can actually see the products up close and determine what it is that you want, but it's also the one where it's you spending time on office supplies instead of working on something that's directly bringing revenue.

Good Luck.

Good stuff from Robert, also remember to negotiate till your heart bleeds with the local big box stores, Office Depot, Staples, Office Max, and the local guys. Most all of them will give you additional discounts on any larger purchase, so make sure to utilize this advantage. These managers have specific instructions to ensure that you keep your business with them, especially on high margin items like printing, ink, toner, which is how they stay in business.