2. Local Online Classified Listings and Forums
Each community usually has a classified online listing of things that are for sale by people in your neighborhood. Check it out, you never know what you'll find. Also, there are quite a few different forums that have classified sections. You'll find everything from video games to HDTVs that are being offloaded by users who wish to upgrade to newer products.
3. Social Networking Sites
While it's probably not good to advertise on Facebook for whom you are shopping for (since they're probably in your network), you can send out a few feelers to see what's up. There's the Facebook Marketplace and other features which allow you to shop. Twitter is different, so don't be afraid to tweet what you're looking for. Your followers might have some insights on where to find it cheaply.
4. Online Stores of Big Box Electronic Stores
There's always a slight price difference on the online version of a store, like Bestbuy.com, and the local Best Buy store in your neighborhood. They also can have steep discounts on certain items, as well as a clearance section, so it's worth a look to see if they are stocking something that you'll like.
5. EBay and Other Online Auction Sites
If all fails, there's always eBay. You can find a lot of things for sale, especially if you don't mind getting some slightly used stuff. If that's not what you're looking for, you can always just select the items that are in 'new' condition.
Since you're shopping early, you can get all of these in plenty of time before the big day that's coming up in December. Shop early and save more, that's our motto during the holiday season.