It’s obvious. Different exchanges have different fees and set their own prices basing on the general market tendencies. Usually, exchanges which are more focused on new traders set higher fees and even higher prices. Platforms for professionals are more loyal. You can easily check prices using BTC calculators on different exchanges (here's one from CEX: https://cex.io/bitcoin-calculator). There’s even a trading strategy of betting on different prices and getting profits from this. However, it’s hardly possible to trade in this way now – as more and more platforms move to the unified price.