The deal with beam scales is the pivot point, the metals used to make the contact points on the base and the knife edges (contacts) on the beam section itself.
Good scales use hardened metal alloys at that point and the knife edges won't dull or flatten, nor will the base contacts get grooved. It's a big deal.
The scale isn't someplace you want to cut costs. All the work put into load development (which includes component costs, bullets, primers and powder) is about finding a load many times to one tenth of a grain of powder.
The scale issue is about repeatability, you need to replicate that sweet load to that same 1/10 of a grain each time. Environmental issues like an open widow with a breeze, a solid support or bench affect the scale each time you use it. The weight of the scale and it's beam, the strength of the dampening magnet, it's ability to "zero" reliably for years is key.
All that said a good beam scale will last decades if cared for properly. I have a Hornady/Pacific model M I got 15yrs ago that's still accurate.
Even second had (used) all metal beam scales are a good bet. Keep an eye on the classifieds here at GBO or watch eBay for awhile, just get one that the seller offers a return if not happy policy.
The Lee Safety scale is cheap for a reason. If your serious about working up and finding accurate loads for rifle I think you'll be disappointed with this plastic scale. If your shooting pistol rounds or will be content with what many call "plinking rounds" for rifle, it'll work just fine.
My first "trickler" was a plastic spoon from the salad bar at the local grocery. Found a Lyman metal trickler at a gun show for $5