As noted, tube amps are considerably more expensive to keep up (and in power consumption) than tube preamps. Another factor is that tube amps usually to have higher output impedance (lower damping factor), which means that system matching is more important, because the actual frequency response you hear will be more influenced by the impedance curve of your speakers.
As an alternative to a tube amp, you might consider trying a modern SS amp made by a tube manufacturer. I'm thinking in particular of the Class D amps made by Atma-Sphere.