Thank you so much for the help, guys! Building from the revision and insight in Blas' response, I went on to finish the code.
Code:
 on *:text:!gamble*:#: {
  if (%floodgamble) || ($($+(%,floodgamble.,$nick),2)) { return }
  set -u5 %floodgamble On
  set -u2400 %floodgamble. $+ $nick On
  if ($2 isnum 1-50) {
    var %randgamble = $rand(1,100)
    if (%randgamble <= 70) {
      writeini -n Points.ini $+(#,.,$nick) Points $calc($readini(Points.ini,$+(#,.,$nick),Points) - $2)
      msg $chan $nick rolls a %randgamble and loses! $nick now has $readini(Points.ini,$+(#,.,$nick),Points) SN1PEbucks. 
    halt }
    if (%randgamble >= 96) {
      writeini -n Points.ini $+(#,.,$nick) Points $calc($readini(Points.ini,$+(#,.,$nick),Points) + ($2 * 3))
      msg $chan $nick rolls a %randgamble and wins triple their bet! $nick now has $readini(Points.ini,$+(#,.,$nick),Points) SN1PEbucks! 
    halt }
    else {
      writeini -n Points.ini $+(#,.,$nick) Points $calc($readini(Points.ini,$+(#,.,$nick),Points) + ($2 * 2))
    msg $chan $nick rolls a %randgamble and wins double their bet! $nick now has $readini(Points.ini,$+(#,.,$nick),Points) SN1PEbucks! }
  }
  elseif ($2 isnum) msg $chan You can only gamble in the range of 1 - 50 SN1PEbucks. 
  else msg $chan To gamble SN1PEbucks, use the form !gamble <amount (1-50)> 
}


So the "execution" part of the script with the roll and .ini management turned out to be pretty simple to make thanks to being able to copy and paste parts from the points script that I have.

Speaking of the same section, I found that unless I put the "halt" after the If relation statements, the script would execute both the first or second "If" command AND the "Else" command. Are there more elegant solutions that might save a couple of lines of text? Or is this the best that can be done?

One last question: I would like to add another bit of script to this command. If %floodgamble.$nick is on I'd like to whisper $nick (as opposed to to messaging the channel) that they need to wait 40 minutes since their last gamble. I have a json script going but I haven't found resources on how to whisper via a script/command. What should I look into to get this started?

Thanks again for the help.

P.S. Anyone who comes in with a working points system wanting to adopt this script for their own use, just edit the currency names and flood timers to match your preferences.