My vote is for a triple poise beam scale. Personal preference is for the RCBS 505 model. More $ friendly than the 510 or 1010. The difference is the 510 and 1010 have a screw micrometer adjustment while the 505 has all sliding adjustment which is easier to read IMO. The 1010 self stores in its own cover/case, if that is important to you.
The Dillon eliminator mentioned earlier is basically the same as a 505.
You should be able to find 505 used for around $40. With a used unit, as long as the beam is straight and the bearing surface (pivots) are smooth it will last you a lifetime.