financial model

Hi everyone - I'm stuck trying to write a formula for my financial model. If anyone can take a stab at a solution, it would be much appreciated.

I'm trying to write a formula that will equally distribute revenue either over the next 1 month, 2 month or 3 month period depending on size of the deal.

Details:
Sales will fit in 1 of 3 categories. Less than 25k; between 25k & 100k; greater than 100k.

- if under $25K, recognize in next month (month N+ 1)
- $25K-100K, recognize in two equal parts in months N + 1 and N + 2
- over $100K, recognize in three equal parts over 3 months
N + 1, N + 2, N + 3 ...

thanks