You can build a decent tube preamplifier for under a grand, and quite a few manufacturers have done so: the MFA Magus), the Conrad-Johnson PV7, the Lazarus Cascade Basic, the Audible Illusions Modulus. But a tube power amplifier for much under a kilobuck? That's just not possible, although the Quicksilver monoblocks retailed for just under $1000 when they first came out. It's the transformers in particular that make tube amps so costly to build.
So if you're on a budget, you might combine…