Well, time is the issue. I haven't done a boot sale for years, but used to sell at them quite regularly and loved the cut and thrust of bargaining, the fresh air and the friendliness. Whether I'd really start again at my age I'm not sure, but it is a nice idea Ieven if it is only a fantasy, the attraction of turning unwanted and free plants into cash.
I really hope that you have a great time turing your vision into reality in the garden and that the end result is all you hoped. Happy gardening!