My first rod was a stick, first reel was a spool of thread held to the stick with a couple bent finishing nails. First hook was a safety pin bent. First bait was a worm. Cost was zero, due to gift of thread and pin.
If you want to catch crappies at low cost, assuming you want a conventional rod and reel, get a light Zebco combo spin caster at WalMart, as many kids of my generation did 55 years ago, re-spool it with 4 lb test line, get some 1/16 and/or 1/32nd Arkie tube jig heads also at Walmart, and if you can find them any small plastic crappie baits -- I use Mr. Crappie or Crappie sliders or whatever in light blue (should be some disagreement here but if I had cash for only one color that would be my choice, where I live). And a long thin float tie it on about 2 feet up.
Then, wait for April or May, again depending on where you live. Walk to a brushy shoreline with a sandy bottom on a slightly overcast morning, and cast out. Don't move your bobber much just give it a tiny twitch once in awhile if you're getting impatient. If there's ripples on the water, don't even do that. If you don't catch anything in fifteen minutes, try another spot. If there are crappies in your water, you will catch them.