Before Crash 2.0 fake IDs (up to SR3 R12) cost basically R²×1000¥. After the crash they only cost R×1000¥, so they are much cheaper now (although they are also capped at R6).
One of my house rules (not included in the table below) is that even post crash, Ratings above 6 are available, but they cost R²×1000¥. These high rating IDs fit the concept of "grown" over time rather than created now. The reason that they are cheap compared to pre-Crash is that really cheap R1-6 IDs would devalue even the really good ones.
For example a pre-Crash SR3-R12 ID would cost 120,000¥, the equivalent post-crash SR4-R8 ID would cost my players 64,000¥.
CODE
SR3 RAW R²×1000 SR4 RAW
1 1,000¥ 1,000¥ - -
2 4,000¥ 4,000¥ 1 1,000¥
3 9,000¥ 9,000¥ 2 2,000¥
4 16,000¥ 16,000¥ - -
5 25,000¥ 25,000¥ 3 3,000¥
6 30,000¥ 36,000¥ 4 4,000¥
7 35,000¥ 49,000¥ - -
8 40,000¥ 64,000¥ 5 5,000¥
9 90,000¥ 81,000¥ 6 6,000¥
10 100,000¥ 100,000¥ - -
11 110,000¥ 121,000¥ - -
12 120,000¥ 144,000¥ - -
13 650,000¥ 169,000¥ - -
14 700,000¥ 196,000¥ - -
15 750,000¥ 225,000¥ - -
16 800,000¥ 256,000¥ - -
17 850,000¥ 289,000¥ - -
18 900,000¥ 324,000¥ - -