Can a inexpensive RJ45 to Fiber optic converters sound better then coaxial ?

I  have seen $$ conversion from RJ -45  coaxial to fiber optic  using Sonore with excellent results but at $2500+ linear power supplies . On Amazon for under $250: people online say buy 2-converters , and the $70  Ifi audio 5 v wall warts are decent much better then stock wall warts ,  will that better the Coaxial setup going to a Uptone audio Ether regen ?  It’s a legit ?  if done effectively noise doesnot travel through a light conductor ,sonore use top Femto clocks regulators ,and a separate power supply is needed i get that but now we are talking $3500

i just want to know what’s possible at minimal cost .i currently use a Ether regen with AQ Diamond Ethernet cables , and the very good Final Touch Audio Callisto USB cable , your help is greatly appreciated, Thank you.