Why did this program not work out? I have my own theories about this.
MR didn't do anywhere near enough advanced marketing on the CE line, details were sketchy and occasionally changing, no firm price or release date was given to the mass audience. There was never a listing on the MR website for the saber, advance or otherwise, that in my eyes doomed it from the start.
Also, and I don't mean this to sound callous, but the announcement that the CE line was going to switch from resin to metal at an affordable price made them far more exciting to a general audience of Star Wars collectors - those who normally would not buy a lightsaber replica because of its high price. That sounds like a good thing, but it would threaten sales of the higher-priced LE sabers, calling into question why customers are being asked to pay such high prices for previous MR entries. The tragedy is that the quality of MR's work would have paid off at the lower pricepoint far more than threefold, so the losses would be offset in bulk sales by a slew of new customers, and there would still be demand from LE fans who wanted numbered, boxed lightsabers.
It also saddens me to see that the Corgi merger is a major contributor to the project's demise, Corgi was not supposed to affect anything yet immediately they've killed a product that would broaden MR's sales to a greater market.
These are just my personal theories. I look forward to hearing from MR about what really went down. And I hope some day when MR's exhausted all the LEs and their various gimmick reissues that they return to the CE line and make a great-looking, great-feeling metal lightsaber prop replica that the common collector can afford, collect, and treasure.