Yes it's worth the cost, especially since the cost is only 1 gold or 5 silver and you likely have tons of each. I usually get at least one 5-star 8-slot weapon out of the 6 or so weapons I get from certain MM stages.
There's also the fact that it came from the official site. Always drill down to the original source, and you can usually confirm for yourself whether it's true or not. If reporters fail to include the source, yell at them and then go find a more responsible reporter.
I'm extremely disappointed at no weapon swap mode. My anger at removing the glitch was only abated by the hope of them re-adding it as a feature.
Hopefully the new Lana costume pleases me.