I'd agree that the Replicas/Inspirations are somewhat overpriced as a purely drinking whisky, but for some of us, the packaging and feel of these whiskies are worth the extra money.
I bought an 1861 Replica because I like Macallan and I was born in 1961. Centennial and all that. And the $200 I paid for the 1861 Replica was a far cry from the price I'd have had to pay for a 1961!!
My 1861 is one of my few bottles I haven't yet opened, it's still sitting in it's nice box looking all 1861-ish in it's hand-blown bottle and replica label. I'm sure I'll crack it on some future occasion, maybe my 50th birthday or something. But until then, I enjoy having it in my collection. Oh, and MJ also rated it 95 in his last edition, the same score given to the 30 yo sherry oak which costs between US$650-800, so it can't be all bad.
I'd say if you have the money and want to have it, then by all means buy it! That's what it's all about, is it not?