Time to convert to a toddler bed

My son just turned 19 months and last night he woke up around 3:30 am. Usually he will cry for a second and then go back down. Last night he woke up crying, and I watched him from the monitor, stand up and then heard a big thud. He fell out of his crib. Luckily he wasn’t hurt, but I’m thinking it’s time to convert his crib to a toddler bed. I was just going to buy a convertible rail because the one for his crib is $99 for a tiny piece of wood. Any suggestions on how to help him in the transition, or toddler rails that worked great for you?