Sensible budget reports?

[Lifepillar]

I have some trouble trying to get and compare budget reports in a way 
that makes sense to me, and would like to know whether I am alone in my 
foolishness.

Consider the following contrived example:

<<<<---- CUT HERE test.dat---->>>>

~ Monthly
    Expenses:Mobile  $100.00
    Assets

2013/01/05 T1
    Expenses:Mobile  $200.00
    Assets:Checking

>>>>---- CUT HERE test.dat---<<<<

For

ledger budget --f test.ledger -l 'd>=[2013-1-1] and d<=[2013-12-31]' ^exp

the result is

     $200.00      $100.00      $100.00  200%  Expenses:Mobile

Since I'm asking for a report over a year, I would expect the budgeted 
amount for mobile to be $1,200, not $100—that is, the budgeted amount 
should, in my opinion, be computed over the requested period and not 
over the period spanned by the transactions. The latter behavior would 
allow me, for example, to easily calculate how much I have allocated for 
the current year without waiting till the end of the year (or adding 
“dummy transactions” with dates 2013/1/1 and 2013/12/31 respectively). 
Does it make sense? Is there a way in Ledger to obtain what I want?

Note that the problem is not that some dates are (at the time of this 
writing) in the future: the same report would be obtained by changing 
2013 with 2012 everywhere. 

Life