*Selling price*

- = model cost × markup %
- = mp%

i.e.

$1 + 20% = $1.2 |
First markup 20% |

$1.20 + 30% = $1.56 |
Second middleman markup 30% |

After implemented GST 6%.

$1 + 6% = $1.06 |
No GST upon raw product |

$1.06 + 20% + 6% = $1.332 |
First markup |

$1.332 + 30% + 6% = $1.84 |
Second markup |

Let assume all markups, p are equal. So after GST selling price total times of middleman transferred.

- 1.06
^{2}(1+p) m - 1.06
^{3}(1+p)^{2}m - …
- 1.06
^{n+1}(1+p)^{n}m

Finally come out.

- Selling price after GST 6% = 1.06
^{n+1}p^{n}m

where

- n = total time of middleman transferred
- p = after markup %
- m = model cost

Increment or Inflation

- = 1.06
^{n+1}p^{n}m/ p^{n}m - = 1.06
^{n+1}

# Assumption

Now we can calculate how many times the product get transfer to end of consumer by assuming all markups are same.