My thoughts on what to price your items.

[Viizari]

Let's start off with this fact: At market price, you have a 90% chance of the customer buying your product. This goes down to 75% at 10% markup and 60% at 20% markup.

By default, you will make the most money from selling at market price. Not per unit, but by completing more sales.
1 * 0.9 = 0.9
1.1 * 0.75 = 0.825
1.2 * 0.6 = 0.72

You can lose out on quite a bit of daily profit by increasing the markup. So I personally keep it at the default.

When to increase markup?
When you can't keep up with your stock refills. If you constantly have (nearly) empty shelves, a good markup might work better for you as you're losing out on sales due to not having stock.
Another reason is for low value items. If you keep them in stock with negligible profits, you can increase the markup to reduce the amount of sales.
It might also work better for large items where one customer can easily empty your shelf leaving the next one without a purchase.

When to decrease markup?
Right now there's no value in decreasing the markup. There's no system in place that impacts your shop by customer satisfaction. So, decreasing the price will lessen your profit and force you to refill more, with the only benefit being your personal satisfaction at keeping all your customers happy.


So, all in all, the most optimal way is base market price (roundup for ease), with enough refill staff to keep your shelves filled.

[Oblivion]

selling single cards = up up that ♥♥♥♥
normal products, just market and sell more 100%

[Viizari]

Indeed, single cards just mark that ♥♥♥♥ up.
Though I don't even bother with single cards. Too much a hassle. Especially later on.

[Goremanslizer]

exactly what I was looking for. thanks for your analysis.