You've been with out tubes for about a year and a half which says that you can live without them. Before making a final decision ask yourself "What if anything am I missing?" If you can't answer it you do not need tubes. So there is no longer a need to hold on to them.
For resale, try a retailer that you know and ask her/him what they are worth. Have not dealt with Upscale Audio but have read good things about them and they might be a good source of information. Where you to sell them yourself, the question becomes "Are there enough there to compensate for the time and energy involved?"
Beyond that it is just acceptance of what your answers are.
For resale, try a retailer that you know and ask her/him what they are worth. Have not dealt with Upscale Audio but have read good things about them and they might be a good source of information. Where you to sell them yourself, the question becomes "Are there enough there to compensate for the time and energy involved?"
Beyond that it is just acceptance of what your answers are.