25 year old thermospas is it terribly inefficient compared to the newer models

I have A 25 year old thermospas Manhattan hot tub.

I don’t use it myself but my adult kids do. I live in the northeast and keep it running all winter at 103-104. I am wondering if this is an incredibly inefficient hot tub to run and would it be cheaper to replace it with a new to me or costo brand new tub to lower my electric bills. I have no idea but I can only guess this costs me $150-$200 a month to run in electric