ISO elastic waist pull on pants for skinny 3yo

My ds will be starting nursery school, just recently potty trained, and cannot do zippers and snaps yet. I am having a very hard time finding pants (jeans or canvas/twill, no sweatpants, want something that can be dressed up or down) that will fit his skinny little waist, most of the elastic waist pull on pants just fall off him. I have tried with no luck at Sears, Gymboree, The Children's Place, Walmart, Target, Marshall Fields/Macy's, Lord & Taylor, Old Navy. The Lands End climber pants are borderline too big, even with the built in adjustable belt. The Gap Loose Fit Pull on Jeans so far are the only things that come close to fitting him, but I might need to get a belt. I was also able to find a pair of Charlie Rocket pants that fit him really well. I just ordered some pants from Talbots kids because they seem to be cut on the slimmer side. I would really like to keep the price under $30 if possible.

My daughter is a skinny thing, too and I always get her jeans at Target. They have a stretchy waist and fit her perfectly. NOTHING else fits her - she is literally swimming in everything else we tried. The jeans are the Target brand (circo) and I think they're $7.99 each - sometimes on sale for $5.99. They're on a display where other matching pieces (sweaters and shirts) are located as well.

I second the Circo recommendation. AAlthough my DS doesn't sound as skinny as your DS, he was also recently potty trained and the Circo brand shorts and pants fit him best because they have fully elasticized waists. Incidentally, these are great shorts and pants for the price - they look decent, last forever and are perfect for preschool and nursery school.

At that age (last year), we bought the Land's End elastic waist jeans. They were definitely under $30 (about $25, maybe even $17). I have a girl but I think they were made for boys too.

They may have cords too.

Try the Lands' End Jersey Pants (17452-7B47) or Softie Cargo pants (17452-6B41). I had good luck with pants of this style last year from them. I had the worst luck at the Children's Place. Target was a bit better.

GL,
Beth