Example: How to make sure product X has a price of 100 USD at 1-10 units, a price of 50 USD at 11-50 units and a price for 10 USD for 51+ units?

When you add Product X in Megaventory (or afterwards when you edit it), you can define its Default Sales Price. Let's say this is 100 USD per item. You now need to make 3 sales pricing rules (under the gear icon, pricing rules, add sales pricing rule):

1. Enter a name, eg Sales Rule Tier 1

1. Set the Base Price to be the Default Sales Price, 
2. Set Use this Pricing Rule for Specific Products (pick Product X), 
3. Click at Insert

2. Enter another name, eg Sales Rule Tier 2

1. Set the Base Price to be the Default Sales Price, 
2. Set Percent on Base Price at -50%, 
3. Set Use this Pricing Rule for Specific Products (pick Product X), 
4. Check the Valid for a specific quantity range box, 
5. Enter Minimum = 11 and Maximum = 50,
6. Click at Insert.

3. Enter yet another name, eg Sales Rule Tier 3

1. Set the Base Price to be the Default Sales Price, 
2. Set Percent on Base Price at -90%, 
3. Set Use this Pricing Rule for Specific Products (pick Product X), 
4. Check the Valid for a specific quantity range box, 
5. Enter Minimum = 51 and Maximum = 100000,
6. Click at Insert.

Now whenever you create a Sales Order for Product X, the Pricing Rule corresponding to the quantity you're selling will come into effect and automatically apply the correct price (100, 50 or 10 USD).