I have 3 "beam" scales. RCBS 505, 5-10, and a 502. I would trust any of them to load small loads. Why, because I have done them many times, with great results. I also have an RCBS 1500 Chargemaster. It is accurate to within + /- .1 grain. I like it a lot, but I still trust the beam scale more. However, I have pretty much stopped using the beam scales because of speed. They seem to do a good enough job. I have loaded very accurate small loads with it. I think a digital scale would work as well as a beam scale, but I think you would have to pay more than $20 for one. I would think you would have to pay as much if not more to get the quality of a good beam scale. It really comes down to personal choice, but which ever you decide on, do not go cheap. Many people have a powder thrower and just use a scale to check their weights to make sure they have not moved. To get consistant loads, you have to develop a "technique", repeating every time you throw a load. Again, it is a matter of what you want to do, but I think you still need a good scale be it digital or beam, even if you use a thrower. It can get expensive. Of course you can just use a scale and dippers with a powder trickler. I started with a used RCBS thrower and a new RCBS 505. I loaded a lot of stuff with it and was my primary way to load. I did not have a trickler and found myself spending a lot of time getting the thrower set up. Now I just punch in the weight I want and push a button.
Good Luck and Good Shooting