I can't see what the branding thing lots of people have mentioned has to do with anything. Branded shoes are not any more likely to fit well or last longer than cheap ones. IMO you might as well have the cheap ones. You can fit the shoes yourself but it involves much more than just asking the DCs if they feel comfortable, you have to check the length, the width and the instep.
Children wear shoes out very quickly, I'm not sure that they would get through clarks any slower than other types of shoes but this is not necessarily what you buy them for. You buy them for the fitting. Like I say my DS has and H width fitting and my dd has a D, standard shoes never fit either of them.
To those who moan about clarks measuring children differently on different days, this is not really anything to do with the fit. Clearly you can't expect clarks to always get it right but this is why you need to learn how to check the shoes as a parent.
Clarks measure as a guide then fit the shoes on the child. I have had this before and still ended up with well-fitted shoes. The only problem I've found with clarks is that the weekend staff are not as well trained as the full time staff. The best way to get well-fitted shoes is to be knowledgable yourself, visit a shoe shop which measures and fits shoes on the feet, get the shop to fit them and check the fit yourself before you buy them.
This website is good for learning how to fit shoes. If your child has standard width/shape feet you would be more easily able to buy cheap shoes and fit them yourself. Bear in mind however that children's foot width changes as they grow and width measurement can be affected by the height of the instep - my dd has thin feet but a high instep so certain styles pinch her feet.
hatesponge - Children's feet are still developing until they reach 18 and can be affected by wearing poorly fitted shoes until this time. Wearing clarks/well fitted shoes until you were 13 was not really long enough to give your feet a chance in that you didn't wear them for the recommended length of time. It is very possible that you just have unrelated problems with your feet though. I'm with miss sunny in not really understanding your logic. If i were me I would worry that it was more important to have fitted shoes for my DCs because they might inherit your foot problems.