Ah yes, the Pioneer SP-BS21-LR -- it was love at first listen back in 2011 when I reviewed it as part of Pioneer's awesome SP-PK21BS six-piece, subwoofer/satellite home-theater system. I used the SP-PK21BS package as one of my reference speaker systems in reviews after that and was always amazed by the speaker's sound and build quality. The SP-BS21-LR speakers sold for $130 a pair. It was later replaced by the SP-BS22-LR, which is the current model (the SP-PK21BS package has also been discontinued). The old and current speaker models have the same retail price, $130 a pair, but right now while supplies last, Pioneer is clearing out its remaining stock of SP-BS21-LRs for $51.98 a pair on Amazon, and shipping is free for Prime customers.
The SP-BS21-LR is a midsize bookshelf speaker, it measures 12.6x7.2x8.1 inches and features a 4-inch woofer and a 1-inch soft-dome tweeter. The black vinyl-wrapped wood grain cabinet has curved side panels, and the drivers are protected by perforated metal grilles (they can be removed, but it's not easy).
The SP-BS21-LR sounds a lot better than my recommended go-to budget speaker, the Dayton Audio B652, which currently sells for $52 a pair on Amazon. I recently compared the two speakers head to head, and the B652 sounded coarse and harsh next to the more refined SP-BS21-LR. That speaker produces more spacious imaging with higher definition bass, and voices sound more natural than what you'll hear from the B652.
I also compared the SP-BS21-LR to our SP-BS22-LR speakers, and SP-BS22-LR speakers were definitely more transparent than the older model. If you can afford $130 a pair, go for the SP-BS22-LR.
I'm not sure how long the Amazon deal on the SP-BS21-LR will last; if you're interested don't hesitate.