Good news for anyone who'd be willing to trade in an old phone for a Windows Phone--and likes Xbox Music. Microsoft is currently running two deals: Under the first, customers can trade in an old, working, smartphone or tablet for up to $250 of credit at the Microsoft Store. And if that isn't enough, you can spend $99.90 at that same store for a year's subscription to Xbox Music--and get a free, unlocked Nokia 520 (AT&T) or 521 (T-Mobile) to boot. The second deal is worth $218.90 alone.

So if you play your cards right, you can spend $99.90 and receive $468.90 worth of Microsoft-branded goods. 

Granted, the Nokia 520/521 phones are the lower-priced, younger cousins to the Lumia 820 and 920 models announced last September. The two share the look of those more expensive phones, though spec-wise, they're somewhat inferior. Nevertheless, should you have an old tablet to trade in (perhaps the first-generation Surface?), you could end up with a new phone and about $150 in credit towards the purchase of a $299 Surface 2. 

With Xbox Music, you'll receive 30 million songs--nice. Microsoft will naturally encourage you to keep paying for the subscription when the year's over.

Keep in mind that these deals don't last forever: The $250 trade-in deal expires March 2, and the Lumia/Xbox Music deal expires much sooner, on February 17.