I wash sheets and towels once a week. Clothes (ESP my 8yo son's) after they've been worn once. Sometimes my son burns through 3 sets of clothes in a day.
For the way we live, having fun is usually dirty, sweaty, and comes with a band aid or two. My son climbs trees, plays with the dog, plays sports, digs in the garden, helps cook... and he gets himself and his clothes dirty. If he's just gone out and gotten muddy, he strips off at the door, brushes the mud off and puts his clothes in the machine then fills the load and starts the wash. If we come back from a sport (at least once a day) he strips his uniform off and puts it in the wash. If we've been cooking and he's covered in flour/ sauce/ drips/ whatever... he strips and puts his clothes in the wash.
Lifes messy. Clean it up.
((Now if ONLY I could convince him to wash his hair without prodding. I swear. That boy. Swear to god a few months ago got my "8yo quote for the year". AKA "Mom. Soap's for losers."))
To me, being clean is worth the extra $5 a month a few loads will cost. It just FEELS good to climb into clean PJs and sheets every night (not to mention smells one whole heckuva lot better). The human body produces oils at EVERY age... and the smell of stale sweat or decaying oils is one of the grossest things on the planet to me. Add in "pee drips" from not shaking off entirely, sigh, much less first few years after potty training with periodic tiny accidents... and you have a bed that's been soaked for years in sweat, oil, and urine. GROSS. I mean, drool and snot I supposed aren't so bad (at least they don't smell) but sleeping in old bodily fluids is just something that I will not willingly do, nor make anyone I care for do. Icky. Icky. Icky.
LOL... and just for "just" fresh PJs... 7 pairs of PJs only equal a quarter to a third of a load in my house. Now, I do buy expensive clothes, so they've been worn for 1.5-2 years by my son and have now (the oldest of them) been handed down twice. The suckers stand up to getting worn AND washed. I only buy him new clothes twice a year (pants and shorts). They just *last*.