Tiered Pricing

I've looked at several examples posted on this forum but haven't been able to get any of them to work for my situation.
My pricing is broken down in this manner.
Tiers...........Price
1-1999........$6.21
2000-4000...$9.67
>4001.........$7.31

Depending on how much they purchase the price is adjusted

Examples
If they buy between 1-1999 their cost is $6.21 per
if they buy 2001 their cost would be 1,999*6.21 + 2*9.67 = 12,433.13
Another example would be if they purchased 5002 their cost would be 1,999*6.21 + 2,000*9.67 + 1003*7.31 = 39,085.72
Additional examples below.

I would like to keep the Tiers and Pricing in a table as shown above so that I could adjust them as the pricing changes and be able to show the cost per Tier as in the table below.

Any help you could provide will be greatly appreciated.


Volume.........Tier 1..................Tier 2....................Tier 3
1,608...........$9,985.68
690..............$4,284.90
1,133...........$7,035.93
1,268...........$7,874.28
3,218...........$12,413.79.............$11,787.73
15,369..........$12,413.79.............$19,340.00.........$83,114.70
18,765..........$12,413.79.............$19,340.00.........$107,939.46
7,910............$12,413.79.............$19,340.00.........$28,589.41
12,387..........$12,413.79.............$19,340.00..........$61,316.28
4,000............$19,330.33.............$19,340.00..........$7.31

Thank you for the follow-up. The attached workbook contains not only the layout but also some example data to give an idea of what it should do as each tier is met.

Correct. I started this new job a month ago and found out that our customer wants us to show the work and manually calculating each tier is a pain, with what you have contributed this process will be much easier. I've taken the above formula and tweaked it as you have suggest and everything matches. Thanks, I click on the star and provided "reputation feedback".

Thank you. I looked for it but didn't think of choosing tools.