I got my oil changed yesterday at one of those Grease Monkey(TM) shops. They're annoying because they always want to upsell you on stuff (and yet I keep going back). This time they wanted to sell me a PCV valve for about $17.00 and an air filter for about $20.00. I know the air filter was about 4 times cheaper if I bought it myself. As for the PCV valve, I'd never changed one out, but from the looks of it, I knew it was pretty cheap to buy. In addition, they had it out in about 30 seconds, so I knew it wasn't hard to replace either.
Today on my way home from work, I stopped into an auto parts (Auto Zone) store to get a PCV valve and an air filter. The PCV valve cost me about $5.00 and the air filter would have cost me about $5.00, but I opted for the snazzy KnR filter that lasts for the lifetime of the car. I got out of there for about $45.00. For my money, I got a new PCV valve and an air filter that will never need to be replaced. If I'd opted for the Grease Monkey(TM) parts, it would have cost me $37, but I'd still have to replace the air filter every 12,000 miles. I figure if I drive my car for 96,000 miles I'll break even on the KnR filter, although I haven't factored in inflation against the potential ROI if I'd bought the cheap filter and simply invested the other $35. If I always bought Grease Monkey(TM) filters, then the KnR filter would pay itself back in about 24,000 miles.
So anyway... Now that I had this PCV valve, I needed to install it. After a bunch of poking around, I found it sitting right next to the oil cap. It was incredibly easy to replace. I just pulled out the old one and plunked in the new one. Didn't even require any tools.