Authentic porcelain items from the "Every Day" service of the Alexander Palace (and others) come up for sale rather often. I and a family member have bought several. Of course as always, two caveats: (1.) Use a reputable dealer (some names have been suggested in earlier postings in the Forum) and (2.) condition! However, if you are willing to settle for less than perfect examples (rim chips, hairline cracks, staining, rubbed gilding/emblems, etc.) then the prices are fairly reasonable. Always get a reasonable period return (after inspection) agreement and "black light" the items. I failed to "black light" a rather impressive Chinese Export mug until years later and was disappointed to find a number of areas of VERY WELL-DONE restoration which was not memtioned in the bill of sale! I cannot be certain that even the dealer knew of its restoration. Too late now, but to all eyes, it remains a wonderful piece.
