If you can produce that "custom PCB" for less than $40, including paying yourself, say, minimum wage for schematic entry and PCB development, plus PCB fabrication, plus shipping for the PCB, plus parts, plus separate shipping for the parts, then ... you're doing really well! (perfboard is more ambiguous, I guess.)
But PCB design and even perfboard construction are probably not on the list of "beginner skills" for most people, anyway. And may not even be on the list of skills they're interested in acquiring.