I have a product I would like to sell but I can only take an order if it's more than 100 units.

If someone would like to order 50 units, that would be fine but they still would have to pay for 100 units.

Where it gets tricky is that when if it's more than 200 units, 400 units or 600 units, the rate per unit become discounted by $100.

I set up my price rules and the unit range to price change works fine.   Except when the order is between 1 and 100 units. 

I'm trying to impliment this logic:

1-99 units = $500 flat rate

100-199 units = quantity * discounted_rate_1

200-399 units = quantity * discounted_rate_2

400-599 units = quantity * discounted_rate_3

600 unit or more = quantity * discounted_rate_4  - bulk_discount_rate

Any help on creating this price formula ?

Another options is to make the minimum amount 99 units, that would eliminate anyone trying to order 24 units or 10 units . .the smallest amount you can order is 99 units . .that way my quantity * discounted_rate_1 can be used and I don't have to worry about the flat rate option.

Any suggestions ?

I don't see that field.  Am I missing something ?

These are the fields I get when I do inline editing as follows in order:

Product ID, Product Name,  Item code,  Description,  Image,  Price,  Sale Price,  Sale Start,  Sale End,  Stock,  Featured,  Not Publish (Disabled)/Coupon,  Vendor UserID,  Date created 

I did not see that field.  Is there perhaps something I'm missing in the Store Configuration ?