I would expect that a handful of retroreflectors, along the lines of lunar laser ranging, would be much less expensive and work about as well if not better. A radio beacon can give direction, at least within the precision of whatever array is used to locate it, but it does not directly give distance. And, with a reflective system, you can get extremely precise radial velocity by measuring Doppler shift, and all the fancy equipment needed is right here on Earth where it’s easy to maintain and upgrade. Doppler measurements of a remote beacon are dependent on the quality of the remote clock, which adds complexity and dependence on gravitational redshift at the beacon [0].

[0] I haven’t tried to calculate how much this would offset the apparent velocity, but it seems very likely to at least be detectable.