That sales number is because these speakers were No. 1 Rated by Consumer's Reports in one speaker test. They were also only 69 bucks and thousands of guys went to their local dealer with that magazine in their back pocket and said they want the A25.
Now that I have owned a couple pair, one pair SEAS drivers and one pair Scanspeak drivers, I appreciate their abilities. Although rolled off on top as many 1960's speakers are, the do sound pretty good and have very good bass for a speaker of this size. Most need to have the one electrolytic cap replace to bring back any of the high end that has been lost in that old cap.
These will never by a main rig speaker as I have found a much better small speaker for when I downsize but they are great bedroom speakers where I have used them for years. Recently displaced with the small speaker mentioned, an NHT SB3, available for about the same money as higher priced A25 which range in price from Free to nearly 300 bucks a pair. The A25 value is maybe 150. The NHT need high power they will not do well with your amps but there are some nice speakers available for the same price or less then the expensive A25s that are better. But the A25 can be very satisfying for many.
If you don't listen loud that 2215 might do a fine job with the A25 but I might like a higher powered receiver with less name brand tax such as an Onkyo, Harman Kardon, Luxman, Kenwood, Nikko. But if you need the Marantz name of blue lights, they are available, just gonna cost considerably more for the same power. The Onkyo TX-1500 (II) or TX-2500 (II) would be my choice for an inexpensive great sounding receiver. for one of similar power, I would seek out an HK 330b or 330C or a bit more power from an HK 430. But none of them have the blue lights or the name your friends will know immediately and bow to your greatness as an audio authority for owning those brands that folks pay too much to own, Pioneer, Marantz, Sansui, McIntosh. It's your money use it however you like.