I think old furniture (but 12 years doesn't really strike me as old) is usually better built than anything but the highest of high end available today. Look on your local Craigslist for someone who sews slipcovers, or try for referrals at good fabric stores. I've slip covered my sofa twice and am always pleased with the results.

Ask at fabric stores for names. Or maybe try decorators. You want somebody who does good work unless you want a loose, really casual look.

I found a woman who does impeccable work and she charges about $400 for a sofa with multiple cushions.

You will need a lot of fabric, so consider that part of the cost as well.

Definitely worth it if your alternative is replacing a higher end sofa with something current - new will either cost much more now or be much lesser quality. Excellent USA made furniture is either crazy expensive and/or hard to find IMHO.

If you're like me and a neophyte at sewing who gets easily overwhelmed, don't cover them yourself! I started to make drop cloth slipcovers for our consignment shop sofa and loveseat and a year later, they are still only half done. Ugh. We can't afford to get them done by anyone else so until I get up my nerve to finish them, they'll suffer from an identity crisis.

However, if you are willing to try, there are a bunch of online tutorials on blogs that detail the whole process. Just google "drop cloth slipcover tutorial"

There's not a huge difference in the fabric or labor involved if you are doing a custom fit slipcover vs. reupholstering. $400 is pretty cheap! I would have said that around $500 is the bottom on pricing on that, and I live somewhere labor is darn cheap. And that's why I learned to DIY it. By the time I bought the fabric, I was already around $400, and if I had to pay for labor too, I might as well go ahead and get it actually reupholstered.

I live in the sticks, literally, and our cost to reupholster is about $1200 for a small sofa or a love seat. Not including the fabric. Around here it is much cheaper to have a slipcover made, around $700 plus fabric for the same size. Price isn't everything, though; if you like a loose, relaxed look and need to launder the covers frequently, a custom slip made of prewashed, washable fabric cannot be beat.