Free or pay to get. Which one is by far the best?
This would only take a few lines of lua.
Use the hook for when an entity is spawned. Then add a variable to the player with the current time like ply.lastSpawned = CurTime() . Then in the same hook function check if a preset time delay has passed and return true/false for the entity spawn hook call.
FPP (Falco’s Prop Protection) has a pretty nice anti spam system