I'm partial to buying the lots or pallets. But if I'm really hard up for money, I hit the consignment sales really hard. I charge a 30% all inclusive commission so I can beat all the other brick and mortar consignment places in my area.
I post my ads on Craigslist and Facebook. I also put up flyers at the grocery stores, coffee shops, and other local businesses. Also colleges. I'll even stop by my Mom's quilting club meeting to spread my word. Just make sure everyone knows why they should use your service versus doing it themselves.
A couple weeks of doing that and I've got enough cabbage to go buy my own lot or pallet.
Heck, if you're not looking to make a whole ton of money, the consignment thing might be a great avenue to explore. Build your brand in your existing network of friends and family, and before you know it everyone knows you as the go-to guy for ebay.