I'm HIGHLY passionate about the Minimig V1.1 board. It's awesome, period.
It's hardware and feels like hardware, it's very different from a software emulator. It feels like a souped-up Amiga 600 to me.
If you just want to use ADF images, you don't need the 4MB upgrade or the ARM controller.
You just need the basic board and ask Loriano (TheDaddy) about a case, because he makes incredible ones.
As an extra, even without ARM, you will get 2 disk drives and hard disk support (a 50 MB HDF will be pretty fast!). You can HD-install those games with crazy floppy numbers anyway (Monkey Island II comes to mind)

And yes: buying old hardware is wasting money when you can get totally new Amigas like the Minimig.
I've yet to find a game or program that doesn't work with current core releases.
Go for it, you won't regret (unless you consider getting MikeJ's FPGA ARCADE... but I've yet to see the new cores for it).