Stupid Scales

I recently bought just a Sundial analog scale that I've been weighing with everytime. Once in a while though I would use an older Taylor Lithium digital scale. And my weight always increases by 6 pounds when I use it compared to the analog one!! It's really discouraging. And I don't know what one is actually accurate so I tried to tell using my work out weights. I had two 3 pound ones. And each showed 6 pounds on the scale. So I don't understand what the deal is. I put the scale in the exact same place. And even tried 3 different locations today, all being the same results. So I feel like splurging on a new scale would be okay. What would you prefer?