No Bulk Discounts

In the shops that are found in video games, it's very easy to buy up a bunch of items (healing potions, arrows, etc.) at one time in a single visit. However, it's even harder to convince shopkeepers to lower their prices when you do purchase bunches of items as opposed to one. This is very often Truth in Television, as apart from certain retail store-specific sales, discounts on multiple items are generally not given.

Since this trope is prevalent in video games (especially role-playing games), only exceptions to the rule will be listed below.

Tabletop Games

 * In the classic Traveller supplement Book 4 Mercenary, military items (weapons, ammo, vehicles) could be bought at a discount which depended on how many items you bought, anywhere from 20-60% off.

Video Games

 * 3D Dot Game Heroes does this with most of its consumable items (arrows, bombs, Warp Wings, etc.)
 * The original NES version of Final Fantasy III allowed you to buy 1, 4, or 10 items at a time, giving you a 10% discount for 4 and a 20% discount for 10.
 * Final Fantasy IV applies a discount if you buy more than four of any given item.
 * Pokémon games have shops that may give you a free Premier Ball if you buy ten Poké Balls at the same time.
 * Note: Premier Balls have the same catch rate as regular Poké Balls, and no added bonuses, so it's essentially 11-for-the-price-of-10.
 * Aerobiz and Aerobiz Supersonic: Though the game does not give you discounts based on the number you buy, you will usually run into opportunities to purchase planes at half price for a turn. Those make good opportunities to bulk up on large, expensive models.
 * In Sub Culture, the bulk discount works against you: the prices of "market" goods (goods that are no use except being sold) increase when you buy many of them, due to supply and demand. Conversely, the more you sell goods, the less they're willing to pay for them.
 * Exploitable in Fable to gain wealth, as the price of an item is fixed according to the quantity of the item that a merchant keeps at one time. Since you can buy any number of items for the price of the first one, buying bulks at once and selling them back to the very same shopkeeper is a way to gain virtually infinite wealth.
 * Played straight with most items in Maple Story, but some shops sell stacks of 2000 arrows that are cheaper than buying 2000 of 1 arrow at another shop.
 * The Elder Scrolls III: Morrowind's Merchantile skill was best trained if you bought and sold things one at a time, but buying a lot in bulk usually made the "haggle a few gold from the price" work more smoothly. Haggling like that trained the skill faster, which simulated increased shopping savvy by deflating buying prices and inflating selling prices, but not as much as individual sales. On the other hand, given that the formula governing the Merchantile skill caused prices to rise and sales to drop again at around 50%, bulk shopping was probably the better tactic.

Real Life

 * Actually happens rarely in certain stores where you can see such deals as $1.99 each or 2 for $4.
 * This trope was studied as part of an experiment concerning advertising. In particular, the bulk bundle provided more profits despite being less cost effective.

Inversions

 * Inverted in Dwarf Fortress. If you offer to pay more for certain items, the caravans will bring more.
 * In Alternate Reality, attempting to buy one more than one item at a time could result in the shopkeeper cheating you when doing the math.
 * Shopkeepers in Mount & Blade charge higher prices for items they have fewer of, and items are purchased one at a time, so the more of something you buy, the more each subsequent one costs. (They also pay more for items they have fewer of, so buying an abundant commodity in one town and selling it in another town where it's rare is one of the faster ways to earn money.)
 * In Flimbo's Quest on the C64, the "bulk" version was even dearer: A Scroll costs 400 coins while a Super Scroll which is as good as all the Scrolls for a level costs 2,500. However, no level requires you to collect more than 6 scrolls so it's never going to be cost effective to buy a Super Scroll (as opposed to say, simply buying each Scroll one after the other.