We did Robeez or knockoffs until about age 2 as their primary shoe. I had one pair with a slightly tougher sole, such as Tredz or a very flexible StrideRite. Most of them were $20 or less for brand-name stuff and under $15 for the knockoffs. From age 2+ we mainly get StrideRite outlet shoes and knock off crocs.
The latest pair of tennis shoes for DS1 were a killer, though. I paid $30 at RackRoom for Nikes. He has moved up to 'kid' sizes (11+) so the prices are higher and the selection of non-tying shoes is even smaller. Our SR outlet isn't super close, so it is usually a couple times a year thing, but his shoes were way too small and hurting his feet so we had to find something local. In the smaller sizes, I would usually find something at Payless or Target, but couldn't do it this time. Even the Walmart ones were $20 and only came in whole sizes which were too big/small so I figured it was worth $10 to get a decent pair.
Mama to three boys ('03, '05, '07)