I know you don't want to break the bank. I've had the spring scales off and on over 40 years. When I bought my Easton Digital scale I was finished buying scales.
I love the thing and use it on every bow I own. I use it to check draw weight at bowyer's spec and at my draw length. It does cost 1-2 times as much as a dozen arrows though.
There are a few things like this that are critical to archery for me; grain scale, bow scale, and chronograph. I also have way too many fletching jigs. The only one I use anymore is the first one I bought back in 1975 - a Bitzenberger.