Question about baby clothes

So I am so in love with the vintage looking rompers and bloomers and bonnets etc. for my little girl. I’ve gotten a few second hand for a portion of the retail price which is amazing. But I’ve seen some almost identical pieces of clothing on eBay from Chinese wholesalers for like 20% of the price. Does anyone know what the difference is? I mean obviously they are sold by different companies but is there a catch? Are the clothes from China defective? Do people who own these little boutiques order them wholesale from China? If I were to buy a romper here in Canada at a children’s boutique it would cost around $50 CAD but then I can find and identical one for $7 CAD on eBay shipped from China. If anyone could help me out with this or has any experience please let me know. I love supporting local businesses as well so I do but as much as I can here but sometimes I just can’t afford it.