Abelo is cheaper for a lot of stuff, they also have a first rate customer service/engagement.
Thornes have always been geared up for the hobbyist with money to spend on gadgets and who don't always worry about the cost (remember that 'modern' beekeeping in this country was once primarily the pastime of dilettante middle class retirees and retired colonial colonels!)
However, their 'second quality' hive parts and frames, very much like Maisemore's are hard to beat on cost or quality. You usually find that most of us have different 'favourite' suppliers for different things.
It pays to shop around, especially with the new players now on the market such as Ian at Old Castle farm, Simon the Beekeeper, and others.