My first time ordering custom buttons to be made on a large scale (100) was made with Pure Buttons who I found through a Google search. From the look and feel of their site, I felt comfortable ordering with them and that they weren't a scam site or anything. Ordering was also super user friendly and I found myself distracted with browsing other promo items (stickers, button 4-packs) to even complete the order! Everything was super cheap and reasonably so for the result.
I ordered the same image in two different colors and am absolutely thrilled with the result. I got my little package a week-a week and a half later in its shiny glory. Some of the pinbacks had been bent so they came out of the button itself, but pinbacks are pretty cheap in general and can be easily bent back.
I chose not to have digital proofing done for me to save money ($10.00 extra) and also because I felt confident in my resizing/design on Photoshop. The template that PB has on their site is a great help.
The buttons were for my senior art show and everyone loved them, but WHO DOESN'T LOVE BUTTONS??
I will definitely order with Pure Buttons again and use their sticker coupon that they included with my order. Wee!!