Hi
When the puppies were first born I used a digital kitchen scale with a bowl on it. As soon as they reached the 6 lbs mark I had to quickly figure something out.
I decided to use a mid-wife idea. I purchased a digital hanging scale then I use a reusable cloth shopping bag (a mid-wife uses a cloth sling) and place the puppy in it. This method really helped solve the problem of a wiggling puppy trying to escape weigh in. It was way less expensive than the baby scales. The one I purchased was very accurate, I compared it to my digital kitchen scale and the vet scale and it was right on to the ounce.
When I did my search I made sure the scale had a tare function so I wasn't weighing a bag. You can search for fishing scales or even luggage scales.
I purchased this one on amazon for about $15:
http://www.amazon.com/American-Weigh-H-110-Electronic-Hanging/dp/B005XPFR2S/ref=sr_1_1?ie=UTF8&qid=1339936595&sr=8-1&keywords=American+Weigh+Scale+American+Weigh+H-110+Digital+Hanging+ScaleGood Luck!
Mary
ashevillegoldendoodles.com