Well, they sort of do work as designed...exception being the buggy preview. Data Merge is really designed, I think, for things like labels.
The least expensive option that probably can do what you need would be Em Software's InData.
http://emsoftware.com/products/emdata/
I use Xdata in QuarkXpress. It requires a bit of "programming" in setting up the merge, but it is pretty extensible and powerful as far as merges go. If you can ever swing the cost InCatalog or Teacup's catalog plug-in, though, those would be better options. I'm partial to Em's stuff and so lean that way.
Merging using ID's built-in capability is more a one-time, then fiddle around type of affair. Even with the master page option, you can thread all the frames using a script, delete all but the first page/frame, then automatically flow to new pages. I have built catalog sections that way.
Another option, also not for the faint of heart, is using XML. Probably a (far) larger learning curve than learning any of the mentioned plug-ins.
Mike