Python 2 - 62.6 points
This code is both the generator and the core of the quine. It expects you to provide a length on standard input, and prints to standard output a version of itself of that length (larger sizes get a trailing comment full of junk).
So, if you pass it 62, it prints itself (this is the minimum size). If you call it with some longer length (up to the maximum length of 3231), it will produce output of that length. Any version will be a quine if passed its own length.
The length limit was the result of my attempts at minimizing the number of characters used. Supporting more lengths was costing more in points for code length than it was reducing the penalty for a limited range. It's not hard to make a variant that will work for unlimited sizes, but it will need to be longer by about 20 characters (and so score worse).
Note that requesting a shorter length than 62 will produce output of the desired size, but that output will not be working code. Passing a larger length than 3231 will produce the 3231-character version of the quine. Passing something other than an integer will raise an exception.
- Generator length: 62 characters, 62 points
- Minimum quine size: 62 characters, 62 points
- Number of supported sizes: 3169, 1.2 points
- All sizes between minimum and maximum accepted: Half off all points above.
- Total: (62+62+1.212)/2 = 62.6 points