I have purchased the John Murphy plugin, both Bollinger plugins and the Alex Elder plugin. I think all seem to work within the scope of their authors' approaches to the market, but if I had to do it again, or choose just one it would be Elder's far and away.

Having read his books and understood what he's getting at, I use his plugin on my default chart designs. However, I'm heading more toward a mechanical system design vs. his discretionary/mechanical approach so will likely incorporate more-specific entry/exit strategies than his, which rely more on subjective decisions after indicators trigger a "take a look at this" condition. No matter what approach you take to the market, his books are well worth reading for the psychology perspective alone (but there's a lot more to it than that).

And FWIW, the best price on the Elder plugin is at his own site elder.com.

Not disparaging the Murphy and Bollinger packages; I just don't use them much. If you like the approach of either or both men, they're both worth having.

3-for-2 is a decent deal, but if you don't need all three it's not. I did some web searching and found good prices on my plugins two years ago vs. buying directly from Equis.