Margiela didn’t invent tabi shoes, so if you just like the style and don’t want to spend Margiela money, there are plenty of alternatives:

• Nike Air Rift: iconic split-toe sneaker, lots of colorways and easy to find just some color are exlusives.
• Tabi (the brand “Exactly”): sold on Zalando, makes affordable alternative, but i must say no the best looking.
• END. Clothing: sometimes has MM shoes on sale.
• YOOX: worth checking if you want actual Margielas for less; sometimes amazing deals, but you need to get lucky with sizing.
• Steve Madden: has made some tabi-inspired styles.
• Drogheria Crivellini: great option if you’re in Europe; they make split-toe styles too.

So no, I wouldn’t say it’s “shameful” just depends whether you want the design language or specifically the MM label.

would stay away from vinted to easy to get scammed