I was wondering whether is would be possible to have the endless copper mine replace the coal/iron mine in the grand and marvellous all-in-one pack, because:
1) There are only 6 copper mines and for sword book production you need quite a lot of copper. Having just the six mines upgraded to level 2 and buffed is just not really enough, so I think it would be much more beneficial to most people.
2) I have always found that getting only one endless mine for 20k gems is a really steep price (I really like these packs!).