One thing I don't skimp on is tennis shoes. Well, let me correct myself, I usually don't skimp on tennis shoes. However, I recently bought a cheaper brand of shoes that only fit my daughter so-so, and within 2 weeks I was giving them away to someone else who needed a pair of shoes. Not sure why I bought them, but I think I was just trying to get the back-to-school shopping over and done with! Had they been horrible I would have tossed them in the trash, but I think they will work for someone else's foot just fine.
I think that having a good fitting shoe on a kid's feet is important, but it is especially important for kids with hypotonia; the fancy word for low muscle tone. Low muscle tone means that the muscles are floppy and not as quick to respond as they should be; that is why these children may fatigue easily, seem clumsy or fall, seem lazy, or are behind in gross motor development. Low muscle tone and muscle weakness aren't synonymous, as kids can have weakness without having hypotonia. But kids with hypotonia are generally weaker than their peers with typical muscle tone (notice I didn't say normal, I said typical).
I don't think to get a good pair of shoes, you necessarily have to spend a lot of money. I can go to Wal-Mart (R) or Target (R) and potentially find a good pair of tennis shoes for a toddler or young child. You want to make sure the shoe is supportive at the sides where the arches are, doesn't come up too high on the ankle as that could limit active range of motion (now there are some kids that need a higher shoe such as a boot, but only if it is not too rigid), is flexible enough to bend the shoe in half, and has a "toe off"- look at the front of the shoe and it should round up slightly on the bottom surface of the shoe, just like a running shoe does (not like a flat surfaced Keds (R) shoe). I find that Smart Fit (R) shoes at Payless Shoe Source (R) and Stride Rite (R) shoes are typically good for the younger kids. I just bought my daughter a pair of Nikes (R) the other day, but even with such a well-known brand, you need to be careful. That is because everyone's foot is made different. Some people tend to wear the shoe down more on the outside, so that is where they need more support (problem is called supination). Some people are the opposite and wear a shoe down more on the inside and need arch support (problem either flat feet AKA fallen arches, or pronation of the foot). The later of these is more common in kids with hypotonia. For older kids to wear on an everyday basis, often finding a cross training shoe is good, because it gives support in many ways and is not as specialized as a court shoe or a running shoe.
My 15 month old son has worn a good pair of shoes consistently since he learned to walk around the time of his 1st birthday. I live in a hot region, and flip-flops or going barefooted are common, so I didn't push him to wear the shoes before he really needed to. FYI: Kids with hypotonia may be walking hazards when wearing flip-flops or crocs. That is because these shoes don't give enough support. Many kids with hypotonia need a snugger fit with good support, or they will fall often! Let me save you a visit to the ER, toss the flip-flops or shoes without a back!