The usual practice today for fine art prints seems to be selling limited editions, artificially restricting the number of prints to a fixed number, say 20 or 100 for example. As long as the photographer keeps their end of the bargain and does not print more than the promised number, the buyer can be guaranteed to have a limited edition product with a degree of exclusivity. The smaller the edition, the greater the photographer could price their prints and the more exclusive the photo.
I have two issues with this. One is that the photographer is handcuffing themselves at the start. They have to guess the tradeoff between price and exclusivity. The amount of money a print edition can generate depends on the product of price per print times the number of prints sold, the latter capped at the beginning by the edition quantity, and the former set as high as possible but not too high so that there are unsold prints in the edition. The problem for the photographer is that if a particular print is unexpectedlyy popular, then the price may have been set too low at the beginning and the photographer misses out on the volume of prints they may have been able to sell had the edition quantity been higher. If the photographer places the price too high, then there are unsold prints in the edition which again is a waste, considering the greater exclusivity which could have been guaranteed if the edition quantity had been set lower and hence justified a higher selling price. Finding that balance between price and exclusivity is tricky, especially for someone new to the field.
The other issue I have is that limiting the number of prints to a fairly arbitrary fixed number seems to be contrary to the spirit of photography, where there are no natural constraints to the reproduction of an image, in contrast to painting where one can usually point to an ur-painting. Limited editions try to mimic the exclusivity which buying a Monet, or van Gough gives a collector, which is something which I am uncomfortable with.
As a compromise, I am developing a system of print pricing which allows in principle an unlimited number of prints, however in practice should be self-limiting. If an image is unexpectedly popular, the extra demand can be catered for. This is achieved by using a sliding scale, low numbered prints are less expensive than higher numbered prints. Early buyers of a print are rewarded by a smaller entry cost. If a print becomes popular, late buyers pay extra. This should encourage speculation yet not denying collectors who are able to buy any print at any stage, albeit at prices reflecting the popularity if the image.
For simplicity, I have adopted an exponential pricing structure. Print N=0 is the photographer's proof version and is nominally set a price P. Each additional print is numbered and priced at a fixed proportion r of the price of the proceeding print, i.e. print number N is priced at P*r^N, where N=1 is the first print to be sold. There are two parameters to be set, P and r. The nominal initial price P set an overall scale (perhaps depending on the size of the print, e.g. P=£10 for a small print, £100 for a large print), whereas the rate r sets a scale for the exclusivity. As an example, if I set P=£100 and r=1.023293, then the first sold print would be £102.30 whereas the 100th print would £1000. If I managed to sell the 400th print, it would be £1 million. Naturally this would limit the edition quantity, depending on just how popular the photo was.
For small prints, it may not make sense to have limited editions, a flat pricing may cater better to non-collectors. But for large prints, this pricing structure may have benefits for both the photographer and buyer as it naturally self-limits to a level dictated by the popularity of the image.