The basic deal they have in my area (metro Detroit) is about $120 per 6 months, with the 7th month free. If you purchase for a year, it's about $240 with 2 additional months free.
You also get a key to check your mailbox after the store closes, but the only downside is you can't actually pick up packages after the store is closed. Instead, they put a note in your box that you have a package. At least at the place I'm at, you have to sign for packages when someone is on staff, so you can't come and pick up packages at 2am or something like that (this is a minor issue for me).
I have most of my packages shipped here because it gives me peace of mind to know that packages are not sitting outside my apartment door. I generally trust my neighbors, but people are always walking through my building, and it's nice to know that someone won't just walk away with a package outside my door.
I've also noticed that for large orders (say above $200), some DVD stores use Priority Mail, signature required. Since I'm often not home when the mail is delivered, it's nice that someone at the mailbox place can sign for the package.
The other plus with the personal mailbox is that some retailers (non-adult DVD) I deal with only use UPS, which means that if I deliver to my apartment, I'll get the note on the outside door saying they will try another delivery, or I can arrange to pick up the package at the UPS distribution center (which is like a 30 minute drive from my place). Having the personal mailbox address means I never miss UPS deliveries anymore.
Finally, I like the fact that other people in my apartment complex can't see that I'm getting DVDs delivered every week!
hope this helps,
pb

