It depends what you mean by a beginner guitar.
Like, if you mean a $20 ACME from Walmart, then yeah, it'll probably sound like crap, be out of tune and warp in less than a year and it'll end up at the bottom of your kids junk box.
If you mean a $100 Yamaha... totally different story. They're actually very well made for the price. Not just a great beginner guitar, but a cheap alternative for home studio use too.

It also depends on the age of the kid too. If you're talking about an 8 - 12 year old.. then $100 is about as much as you should bother paying because it's going to get scratched and thrown around. However, if you have a 16 year old, it's a different story again. They'll have more appreciation for the value of what they have, so a decent used quality instrument would be a great idea.