Well if it works out that way - being more profitable - you should just see more books and a stronger market. One of your concerns early on. 
And, I don't recall any official mention of cost reasons for digest size, but that is irrelevant - publishers will do what they feel they must.
In the worst case for you - PDFs have flexibility to be printed - it may cost more and be less convient - but then again PDFs are often priced lower, and instantly available. Plus, you can print and bind it exactly the way you want - and are not limited to the publishers choice of paper, inks, binding or covers.
And with online publishers keeping track of your orders and the option to make personal offsite backups - little things like fires, floods and grandchildren don't have to potentially spell the end of your collection.
(P.S. - I assume those 4 years renovating the 172 Victorian included replacing the electrical - I love old homes, especially with lots of wood and character - but I have no pleasant things to say about their electrical.)
And, I don't recall any official mention of cost reasons for digest size, but that is irrelevant - publishers will do what they feel they must.
In the worst case for you - PDFs have flexibility to be printed - it may cost more and be less convient - but then again PDFs are often priced lower, and instantly available. Plus, you can print and bind it exactly the way you want - and are not limited to the publishers choice of paper, inks, binding or covers.
And with online publishers keeping track of your orders and the option to make personal offsite backups - little things like fires, floods and grandchildren don't have to potentially spell the end of your collection.
(P.S. - I assume those 4 years renovating the 172 Victorian included replacing the electrical - I love old homes, especially with lots of wood and character - but I have no pleasant things to say about their electrical.)
