Tier pricing...me thinks this is an awful idea. I'd rather sell 10 prints at $200 rather than 4 or 5, then hope someone feels numbers 5-10, 11-14, etc. are worth 20-100% more just because there's only yeah many left. This works when you have a universally recognized name and mayhaps only three (i.e) prints remain of a particular print. Just my opinion and not based on real data.
Just a thought on tiered pricing - I'm not saying it works or doesn't, but the psychology behind it is that you encourage the early-adopters, so to speak, to buy early, because the price is going to go up. You also encourage the early adopters to buy because you are demonstrating the investment value of their purchase. It's a marketing strategy. I find that it does work, combined with highly limited editions of your prints. I also like very limited editions because while I enjoy making images, I don't like doing drudgework of making umpty-dozen copies of a single print. I'd rather make an image, make some money from it, then move on to making a new image. In part I look at the tiered pricing as a way to extract extra value from someone who is making me print the same image for the nth time.