For one person on July 4-7, Florencio can be booked for 420€ (trivago member price), Orosol can be booked for 415€ (hotels.com), Tropical can be booked for 388€ (booking.com). The Red can be booked for 370€ (trivago member price).
You have to shop for hotel prices these days, use price comparison sites like trivago, kayak, check24. Different channels have very different prices. I recently booked Occidental Ibiza in mid-May for about 80€/night on check24, the asking price on the hotel's own website was twice as much.
I personally pay less for Ibiza hotels these days than I did 15 years ago. Simply because I learned to shop around and not to insist on being in a specific hotel. Going to a sea view balcony after waking up to see the sunrise isn't worth extra 100-200€ per night.
50 pounds per night in July sounds like very long ago (or during covid).