Interesting. Majestic Bank used to have a much better rate than other never-KYC, no JS, Tor mirror, type services. Their base fee was 2%. eXch for instance started at 5.5% for anyone buying XMR. Xchange has 3.6% as of writing.
As far as I remember, at the beginning of eXch, the fee for XMR trade was below 2%. Later, they raised it to 5+%, after XMR was delisted from many big CEX, so eXch was one of the few options that offered XMR in any relation and that led to a great demand for this coin on their service.
Also, there is a matter that has already been discussed here in recent days. An exchanger can represent a very low service fee, and at the same time have completely different relations in the real offer.
For example, I always check other alternatives, hence the note that MB was a bit more expensive.