HDCD players are great because you can play HDCD disk on them. However, as often mentioned, HDCD disks are few and you really have to search for them unlike SACDs or DVD-As.
But for me, playing HDCD disks is not the foremost reason for acquiring an HDCD capable CD player. HDCD equiped players also improves the sound of regular CDs. "For non-HDCD software, HDCD Precision Filtering improves the accuracy of D/A conversion, producing a sound which is more open, natural and less harsh." - Pacific Microsonics, Inc.
I enjoy playing and listening to almost all types of audio CDs on the NAD C542. Heck, I even find it better than the Arcam CD73T. So much has been said and written about the performance of a C542, and all I can say is that, if you can spare the extra pesos go for it. Considering its price I think it would still fall within the budget range.
Just me.