E-Commerce Editable Pricing Capabilities

I’m looking to build an e-commerce site with WordPress and I’m having trouble locating a plug-in for a feature I’d like to include.

I want to have the price of a product change as the number of items purchased increases.

For example, if 100 products are available…
the first 10 are $5
the next 30 are $10
the next 40 are $20
the final 20 are $25

I would need something with an editable feature so I can change the total number of products available and adjust the number of available products and price for each tier.

Is there a way to do this without custom coding?

Thank you in advance for your help!

-S