It is getting a bit excessive imo, yes. But this is what happens when a musician dies - his music gets more popular and respected, and if there is a demand for it (which there is in this case) then every recording ever made short of that person farting backstage is released so that people can make money off of it. Look at Nick Drake for example. There is going to be an album coming out soon with a "lost song" of his on it. You know, like somebody just happened to stumble upon it in the attic somewhere. Like it was really lost in the first place, rather than bought as property by the record company, didn't make the final cut of one of his albums, and so it was saved until further date when they could profit from it. Things like this help sell records.
Personally I don't care much at all about the bonuses and extras, but love the fact that they are remastering Grace, which is one of my favourite albums. If they were releasing that just by itself I would be much happier... but instead they are milking their money out of me. And it will probably work... unless I try and find it at a used CD shop or something.