Well, that certainly took long enough. It's been more than a year since swimming pool and personal health care product-maker Water Pik (NYSE:PIK) announced that it was considering a "potential sale of a portion or all of the Company." Late on Friday, "considering" became "agreeing to."

The buyer in this case is Coast Acquisition, a subsidiary of the Carlyle Group, and it's paying $27.75 per share to acquire all shares outstanding of the little Motley Fool Hidden Gems Watch List pick. The deal represents approximately a 31% premium over Water Pik's Friday closing share price of $21.62 per share. That price didn't have a chance to rise in response to the deal's announcement on Friday, because the buyout wasn't announced until just a few minutes short of midnight.

According to both the joint press release on the subject and subsequent news reports, the $27.75-per-share price values Water Pik at $380 million. But I'm honestly not certain how the parties came up with this number. According to the firm's most recent (and last until it gets reIPO'ed) Form 10-K, Water Pik had 12,286,674 shares outstanding as of Dec. 5, 2005. Multiply that by the buyout price, and you come up with a deal valued at basically $341 million. To get a total deal value, you ordinarily add to that the amount of the target firm's long-term debt -- but in Water Pik's case, there isn't any. On the contrary, Water Pik has $41 million in cash and equivalents. So at first glance, this Fool would rather value the deal at $300 million, even.

The reason this is important is that, although it's too late for investors to get into Water Pik and benefit from the purchase price, it's not too late to use this price to place a "going private" value on similar companies, should they ever receive bids. For example, if Water Pik is worth $380 million, that equals 1.2 times its annual sales; but if Water Pik is worth just $300 million, that multiple drops to 0.9 times sales.

Either way, this suggests that Water Pik competitor Pentair (NYSE:PNR) is an unlikely takeover candidate (it trades at 1.3 times sales, pricier than either valuation for Water Pik). A.O. Smith (NYSE:AOS), on the other hand, trades for less than 0.7 times sales. That would suggest that A.O. Smith is either undervalued or drastically undervalued, depending on Water Pik's precise worth.

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Fool contributor Rich Smith holds no financial position in any of the companies mentioned in this article.