Many people say that buying new is better than buying old, but in reality, there are still many people who buy older equipment instead of new ones. The technology for shortwave radios doesn't necessarily undergo a major breakthrough every two or three years, or even every five years. Therefore, equipment from several years ago will not be outdated, and in some cases, it may even outperform newer models at the same price point. At the very least, it has been thoroughly tested.
Last year, I bought a 7300, a 710, and an 891. This year, I also got a DX10. To be honest, if I had to choose between the 710 and the 7300, I would definitely go with the 7300. Otherwise, I would just get the DX10!