As mentioned previously, there are alot of great pre-amps <1K. Especially on the used market, probably moreso on the used market in hindsight. One of my favorite sleepers is the Anthem Pre-2L(<500)....throw a couple Sonicaps in the output stage($100) and your done. The tubes are common 6DJ8/6922 and there's a whole gamut of choices with that heater.
Mark