Sending large amounts is cheaper for us. So, it should be cheaper for you, too. That’s why you get a discount when you send over 20,000 GBP (or equivalent).
When you use banks and other providers, they’ll charge you more by hiding extra fees in the exchange rate and say their transfers are “free”. We only use the live mid-market rate, and a small, upfront fee to cover our costs. You’ll always know what you’re paying for — and what your recipient will get.