I'd honestly rather just pay a reduced fine than try to fight it, fail, and get a full price fine.
Like racer said... The fine cannot be reduced. here's why...
I'm guessing you were cited for violation vehicle code section 21453(a), right? (That should be on the citation that you recieved.)
When it comes to the fines for each violation of the vehicle code, there are two ways fines are set by the legistlature.
One way is by setting a maximum fine amount (and possibly a minimum)...
{For example it'll say: SHALL BE PUNISHED BY A FINE NOT EXCEEDING $250 BUT NOT LESS THAN $100} and if that is the case, then the Judge has discretion to set a fine anywhere between those two numbers (the max and the min).
The other way is to set a specific amount
{it will say: SHALL BE PUNISHED BY A FINE OF $100} and in this case, the fine is referred to as a
Statutory Fine. Meaning the Judge has no discretion as far as what the fine amount is.
The fine amount for a vioation of CVC section 21453(a) is established in CVC section 42001.15 which states:
42001.15: Every person convicted of an infraction for a violation of subdivision (a) or (c) of Section 21453, subdivision (c) of Section 21454, or subdivision (a) of Section 21457 shall be punished by a fine of one hundred dollars ($100).
Now don't get too excited yet because the $100 stated there is only the Base Fine. The statute also requires the court to collect what is refered to as penalties and assessments which do in fact increase that amount considerably.
According to the Uniform California Bail Schedule the total finje amount for a viollation of CVC 21453(a) is $380. Keep in mind that the total Fine amount might slightly vary from one county to the next. So it might be a bit more or if you're lucky a bit less.
Also, like racer said, you've got a pretty good chance of getting some sort of payment plan or extension to pay the fine from the court. But keep in mind that in either of those cases (payments or extension) they may (I know in L A County they will) charge you an additional $30 or so if you choose to either make payments or pay later.
If you wanna avoid that, then ask for an extension before you appear in court (that should get you 60 days) to save up the money, then (based on your stating you have no defense) show up money in hand, plead "guilty" or "no contest", and pay the fine immediately thereby avoiding the additional fee.