Emily and I had purchased a no-name generic mattress several years back, and it became painfully apparent earlier this year that the quality of our sleep had degraded with the emergence of dips in our poorly constructed nest of slumber. If there is any item in the home to splurge upon, I would say the mattress is an obvious choice. It's where you spend hours sleeping (and more wink-wink), and why cut corners with something that aids in health and comfort on a daily basis?
So when is it time to let go of Saggy McSaggins, your decade old mattress that now has an indentation that perfectly fits and nestles your body? The obvious sign is what your body is telling you. Waking up with sore spots, especially pressure points in locations as the neck, lower back, and hips is an indicator that your mattress is not providing equal body support. Lumps or sags create uneven surface area, and can actually be a precursor for more serious injuries, not to mention less restful sleep. It's time to break the codependency, friend...you've got to let Saggy go.
Also be ready financially. Buying a bed can bring some sticker shock once you enter the realm of quality built sleeping surfaces. When I was 20, I could sleep on a burlap bag stuffed with an nest of angry hornets with nary a problem. Now I need a firm, supportive mattress with better structural integrity and a spring count that nearly matches the price tag in numerals; we're talking about the $1000+ price category (although with the discount noted above, we came well under that figure). A greater spring count with thicker diameter coils and a well constructed box spring/platform bedframe can make the difference in the performance and comfort of a bed.
Seem like a lot of money? Some people will even pay between $5000-$20000 for a mattress, so save up...a good night's sleep pays for itself very quickly. I can speak from experience: upon sleeping on the new mattress, both my girlfriend and I overslept, through our alarms, on consecutive mornings because we both entered the world of Yawny at the Sleepolis and didn't want to return back to consciousness, such was the blissful comforts of a supportive bed. No buyer's remorse here...besides regretting I can't nap as much as I'd like to!