I currently use an Ohaus Scout-Pro with a 6000g capacity, roughly 13 lbs for detail work. It costs less than $200 and when certified this year, it was accurate to the thousandth of a pound. Like Greg, I have been disappointed with many of the scales I've used in the past. However, this one has surpassed all of my expectations. I've also used another less expensive Ohaus ($69 as I recall) with good success other than short battery life.
You really don't need accuracy to .001 lb for relative weights though.
One thing you could do is convert your Wr table to grams or whatever your inexpensive scale is measuring in. That way you only have to do one conversion initially, then every survey after that you are golden.
