Congratulations! Paying off your student loan is a big thing. I remember when I paid mine off.
I have had a home theater for more than twenty years and improve it periodically. So we have a 77” Sony OLED in the home theater with a high end surround system and a 65” Sony LED TV in tne bedroom with a great sound bar. I never notice the picture quality difference unless I really concentrate and then I notice a very subtle tone difference.
In my opinion(for me), if funds were limited, I would just get an LED TV and put the difference in cost into the surround. The difference in picture is so small, with a substantial difference in cost… but in a budget surround system $500 or more can produce a very big improvement in sound and the overall experience.
I would wait to trade up to an OLED until funds are no big deal. Our ratio of TV cost to surround system cost is something like 1 to 8. This is how much value to the experience the sound side gets you.