As 2D's says, the price variation of Avgas broadly follows that of crudes. Somebody mentioned WTI earlier, that is West Texas Intermediate, relevant to Avgas prices in the US, but not (directly) to the UK Avgas market. Ours follows BFO (Brent,Forties,Oseberg) much more closely.
The price of all distillates (eg Gasoil Jet etc) is very high due to a global shortage of refining capacity, and rapidly increasing demand in China and India. The increased refining runs to cope with the demand for distillates has produced a slight surplus of gasolines, and accordingly distillates are now more expensive than gasolines.
Latest prices cif Rotterdam $/ton:
Gasoline 95 RON 551.25
Jet 585.06
Diesel 557.63