Assuming that prior to this your group had a verbalized agreement to split treasure evenly amongst the party members - you are actually being *unlawful* by going against this prearrangement.
You also mentioned something about drug dealers not getting repaid for illicit goods. That's fine, except that drug dealers aren't necessarily evil. What they are is unlawful.
Demon Summoners are evil, but not necessarily unlawful. In fact, most demon summoning cults are extraordinarily lawful.
So what you're basically saying is that the principle of equal treatment under the law doesn't apply to unlawful people. According to that logic, you can murder any chaotic (or even neutral) person without fear of repercussion.
According to that logic, your paladin is Lawful Evil.
Enjoy your lack of class abilities.
Back to the specific matter at hand, it's up to each individual party member whether or not they believe they should chip in for your lost shield. Do you regularly chip in for Diamond Dust for the Wizard's Stoneskin spells? What about paying for scrolls of Remove Curse that the Cleric has to use in order to keep the party from being Mummy Rot'd? How about each +1 Arrow that the Ranger uses? Those are magic items being destroyed due to the expected usage thereof.
Your argument is very much the definition of greed ("Replace what's mine at the expense of everyone else."). The communal life style of most adventuring parties (each gets their own equal share) is exactly at odds with your stated belief. If the entire party believes that what you're demanding is correct, then by all means go ahead and take your money off the top. If even *one person* decides that they believe your claim is unright or unjust, then no. You get your share and the other members of the party can donate some to you if they feel the need to do so.
tl;dr - You're tottering towards LE, mate.
-TRRW