I'm in the same situation. Multiple accounts with a lot of DRM tunes, some I don't even have anymore. It's an all or none decision based on the buying history of the account?

That has got to be the lamest trick pulled. It makes the only possible thing left to do is to DRM break them all for free.

I am about at 500 bucks too maybe a tad more including my kids. But I haven't purchased anything in months because of all this. That is what DRM has done for me. Kept me from spending money on music and now it is going to turn me into a thief and I likely will do it to my children's tunes so I teach them how to cheat too.

Did I mention DRM was stupid?

I was thinking of asking Apple to combine accounts but that is likely pointless.