The problem for most people is that they don't know how to correctly figure COGS (Costs of good sold)
The standard is to mark up 3 X cost or 33% profit. So you have 33% of your cost to cover COGS, 33% cover CODB and 33% Profit.
But because people really don't know how to correctly figure COGS, they get it all wrong and they think $30 for an 8 x10 is surely too much andd ripping off thier client.
Afterall from your profesional lab a 8 x 10 runs $1.99 so x 3 = $6. right? wrong...very wrong
COGS includes the Price of materials, shipping, LABOR (your labor) Packaging (Those cute boxes and ribbons you buy) and when real cost analysis is done in large companies a few things that are part of CODB can be included into COGS. BUTt even if we don't get that fancy and complicated, the biggest mistake people make is not including labor into the COGS.
Now this is not your shooting time. That should be a separate fee. But if it is not and you only charge for prints then even that is included in COGS.
People think since they don't pay anybody to do the labor there is no cost but there is. and when you really figure the time spent, Sorting and culling images, Editing images, Ordering images etc. That time is much more than the actual shoot time. So you need to figure in an amount of time spent doing that and how much per ordered image(File/pose) that would be. Now as far as labor rate, you don't use what you want to make as a business owner because hopefully that would e a LOT. But you use what a standard labor rate may be to have someone do that job.
When you really figure this all out, you actually end up with about $2 for raw goods, $2 for shipping and packaging and $6 for labor for that 8 x 10 = $10 COGS
$10 x 3 = $30
and there ya go