There's a couple of issues that I was hoping would be changed with Legends but haven't been.
The main issue is with disputed bases. They are just worth far too much currently - much more than they are worth.
Take my current game. The humans recently colonized a system that I had a few mining bases in. These mining bases weren't anything that special - they were all just very common or common resources, ranging from steel to caslon. They had reasonable percentages of each but, again, nothing that great.
The human empire would offer me 450K each after they first colonized it! And now, they will offer me almost 700K for each one left!! I can't believe it. Bases that are so unimportant, types they can find all over the galaxy, and they are offering me that much.
Another example in the same game. The ugnari (spelling?) have a research center in one of my recently settled and they would want more than 6 million for the station!! 6 MILLION... why in the world would I ever pay that much for a research station? Granted, it has a 27% bonus but, come on. I can simply build two bases, which would only cost me 1K more in maintenance, and I could get a much higher research output.
Granted, having them in dispute should increase the value slightly as they would give quick access to resources. However, I see no reason why a typical station would be worth more than 50K (unless the resource is in high demand by the empire or the percentage is high), with more valuable resources obviously increasing this value. For the latter example, the 6 million is an enormous amount. Even if I wanted it, I wouldn't pay more than, say, 60K or so for it (since it has a bonus). I can build other research stations anywhere for 5K each.
On a similar note, it would be nice to actually be able to trade bases or planets. Is there any reason this hasn't been implemented yet? It would be a nice feature.