First, lets be honest, limited editions are a marketing gimmick; a fair gimmick that I have used and may use again, but it is still a gimmick.
It's purpose is to artificially create scarcity.
Okay
Quick question -
Do you print the entire edition at the same time? That would be my druthers so as to ensure consistency and completion of the edition.
If you are going to do an edition I think this is the best way, it eliminates any question of reprinting and "busting" an edition number because you can destroy the negative. In your case 1/5th of the negative for an edition could be included with each print, each owner would know without any doubt that they had 1 of 5 and that there would never be a #6 or even a replacement for #4.
However, if you're not sure about demand for the print, this can result in a lot of waste.
If you truly stuck to a 5 print limit that's not really much waste.
If you are doing 5 prints each in five sizes (25), multiplied by 2 finishes in each size (50), multiplied by 4 types of toning (250), and you might consider Carbon, Salt, and other sizes on top of that, it's really not much of a limited edition.
My thought here is that if you are not sure about the demand for a print or if you aren't really wanting to limit your editions to 5 total, don't, just choose a different marketing path.