The big problem with buying RIM is that there isn’t only one big problem

As RIM’s sales sputter and its market value falls, potential buyers are starting to sniff around.

Reuters reports that Amazon took a look this past summer. The WSJ reports that Microsoft and Nokia have considered a joint bid for RIM. Other potential buyers, I’d guess, could include Oracle, Microsoft-without-Nokia, one of the Chinese telecom gear makers, private-equity turnaround shops, and maybe even Apple (at the lowest possible price, so probably not).

There’s no question that RIM is worth something:

• It has more than a decade worth of mobile and smartphone patents, including a stake in the Nortel patent auction spoils,
• Almost $20 billion in annual sales,
• Some 75 million subscribers, including many huge corporate customers,
• And it’s still profitable.
• Its QNX next-generation operating system core exists, and has nothing to do with Android or the patent problem with Microsoft — yet. A company like Amazon could conceivably slip it under the hood of the Kindle Fire, replacing Android. It might even be able to emulate Android apps until developers switch over to the new system.
• RIM has worldwide distribution and carrier relationships, and the foundation of a decent smartphone business.
• It has the basis of potentially interesting platforms, such as BBM.
• It makes nifty little plastic keyboards that some people still think they need.

But RIM also has real problems, most of which are plaguing its ability to reinvent itself, and many of which will transfer over to its new owner:

• Most important, RIM seems lost. It appears to be incapable of delivering present-day smartphone and tablet engineering, software, ecosystems, and design. It’s not just that the BlackBerry and PlayBook aren’t as pretty as Apple’s iPhone or even Google Android devices — it’s that they are only a fraction as powerful, useful, and elegant.
• RIM’s two CEOs, who led the company through its first boom, are still in charge. And for years, they seem to have been oblivious or in denial of RIM’s declining competitive position. The board, apparently, still has their back. (And probably needs to go, too.) But replacing them will also be a mess. So, what to do?
• RIM, based in Waterloo, Ontario, is quite far from the excitement and talent pool in Silicon Valley, which has led the recent wave of mobile innovation. Isolation probably isn’t a good thing in this case. RIM’s buyer will have to figure out whether to slim down its HQ and relocate — costly in many ways — or to try to rejuvenate it within Canada. But it’s not like Amazon or Microsoft would be buying a huge Silicon Valley mobile R&D center here.
• With RIM’s decline, there’s little reason for developers to care about making great apps for the BlackBerry. Some companies still invest in BlackBerry apps, but some of the top apps — Facebook and Twitter, for example — are still made by RIM itself, in partnership with the companies.
• RIM’s growth is increasingly coming from emerging markets and lower-end devices. Things in the U.S. are so bad that its native Canada has recently grown as a percentage of revenue. (7.5% of sales over the past 9 months, up from 7.1% during the year-ago period.)
• The BlackBerry brand, once a cool mark, is now seen by many as second-rate. This isn’t totally unfixable, but it’s yet another uphill battle.

And then there’s the problem that RIM keeps getting cheaper.

When I first argued in 2009 that Microsoft should buy RIM, its market cap was $21 billion, the company was still growing, and Microsoft probably would have had to spend $35 billion to get the deal done.

Today, RIM’s market cap is $7 billion. Absent a bidding war, it might be had for $10 billion, if the board could be talked into it. But it is also in decline, with slim odds of recovery. Maybe in another six months, it’ll be even less expensive.

So, we’ll see. I wouldn’t bet money on RIM being able to fix its problems by itself. But it’s also still probably too expensive for most buyers — knowing that it’s probably going to get cheaper, and that hacking it up is going to be messy.

Barring a miracle, it’s hard to see a happy ending here. And it’s sad. But the technology industry has a crazy way of destroying its laggards. And, on the bright side, perhaps this will soon lead to a bustling startup scene in Waterloo.

Related: RIM’s rise and decline: A 10-year view