I haven't seen the commercials but I purchased one of them.  I have the Namco one with Pac man, Dig Dug, Galaxian, Rally-X, & Bosconian.  I got it here in Canada at Walmart for around $30.  It was neat at first as it simply plugs into the T.V. with 2 connectors, but its not the "real" thing.
When I say real thing I don't mean the obvious like sitting down in front of a table top & dropping in your quarter.  This is what I mean: For example the ghost patterns for pac man are WAY off.  They don't follow the same logic as the original.  I know because there is a pattern when playing if you want to cheat.  Well so I've heard.  

I wouldn't spend the money for one, although I've thought about ripping it apart and seeing if I could use the balltop as one of my controllers.  
