I love books, and most of mine are bought used. There are times it would be nice to share what I have read, but no where to do it.
If you would consider including info on the on line books and how and what they are it would involve the younger crowd. There is still a place for books, old and new, electronic or paper.
With books you can learn about anything and can go anywhere, dream anything. I was taught books are the windows to all worlds and all dreams. We have a used book store in my area that offers 2 for 1 on returns. They have been around a long time so it must pay its way.
It will never be played out.
Depending on your area and the laws governing businesses, I would start very small in your garage or I have seen small businesses start out of storage areas and move up. Put a couple of old chairs and a coffee pot out and your neighbors come and they spread the word.
Time is your biggest problem, time to actually show a profit, time for family life, time to just go, time, time, time.
Money is slow to come and slower still to be profit. The ones that succeed are the ones that can manage time, money and just life without throwing in the towel.
If you keep careful records they will tell you if it is worth your effort. But in the meantime you will meet many amazing people.