Purim Mashgiach, i do not know where you get your halachos from, but I think the haskomo of the poskim is that shabbos shoes are included in clothes le’gabbai kovod shabbos, so although it may be a nice way to be mechabed shabbos, it is not necesarry. The legendary Harav segal of manchester had every beged different for shabbos except shoes.
I personally thonk that if you want to teach children kovod shabbos, you are much better off teaching to polish their shoes esp[ecially for shabbos than to buy them another pair.
Mrs. Katz, i actually overheard your mother in law telling your Isreali siblings that shoes and sandals are a waste of money, and that Yoisef Moikir shabbos used to walk around barefoot.