This series, brought to you by Yahoo! Finance, looks at which upgrades and downgrades make sense, and which ones investors should act on. Today, our top trio of newsmakers includes newly buy-rated Aeropostale (NYSE: ARO) and Eldorado Gold (NYSE: EGO), while Buckle (NYSE: BKE) gets pantsed.

Aer ball
We're still more than two weeks away from the date Aeropostale is slated to report earnings, but Wall Street isn't waiting around for the news. Unable to contain their enthusiasm for this 26 P/E (?!) stock, two analysts are rushing in early and urging investors to buy before it's too late. But is there really any reason to hurry?

It's not as if 26 times earnings was particularly cheap, after all. While it's true that Abercrombie (NYSE: ANF) and American Eagle (NYSE: AEO) cost more than that, your average teen retailer these days is trading for closer to an 18 P/E. Nor does Aeropostale's growth rate look particularly attractive. At less than 12%, Aero's actually growing more slowly than most of its rivals in the apparel store space.

While overall, this is not a bad business -- free cash flow looks good, and the company keeps an admirably large bank account on hand, whilst eschewing debt -- the stock price is simply too high.

Buckle down 
Investors looking for a real bargain are better off shopping the racks at Buckle -- downgrades notwithstanding. Last week, we saw analysts at KeyBanc make the incongruous call that despite being "one of the best managed retailers" out there, it should be avoided because it charges too much for its goods and could therefore suffer if "macroeconomic conditions" continue to deteriorate.

Bunk.

This morning, Janney Montgomery Scott joined the pack of naysayers counseling selling Buckle stock, but two wrongs don't make these analysts right. If Aeropostale is a "buy" at 26 times earnings, then you've got to figure Buckle at 12 times earnings is an even stronger contender. Sure, its long-term growth forecast isn't as zippy as Aero's, but the discount in P/E more than makes up the difference. Putting the final button on the fly of this buy thesis, Buckle pays you 2% to own it, versus Aeropostale's dividend yield of zero-point-zilch.

Leggo my EGO
Last but not least, and continuing today's blue jeans theme, we come to Eldorado Gold (trivia note: historically, the primary purpose of buying denim was because it held up well to the abuse it took when mining for gold.) Stifel Nicolaus just upgraded the stock to "buy," but it's hard to see why.

The analyst says EGO shares should hit $14.50 within the next 12 months or so. But in fact, even the current share price of $11 and change has these shares selling for more than 22 times earnings. When you consider that EGO pays only a modest 1.6% dividend yield and is furthermore growing at a snail's pace of less than 8% per year, the enthusiastic buy argument here looks overstated.

Long story short, production is dropping, while costs are rising, and management is walking back its 2012 forecast -- this may all look like a great "buy" argument to Stifel, but you know better.

Fool contributor Rich Smith holds no position in any company mentioned. The Motley Fool owns shares of The Buckle and Aeropostale. Motley Fool newsletter services have recommended buying shares of The Buckle. The Motley Fool has a disclosure policy.