If it is 15 years old you are getting a lousy picture by todays standards. Seventy five inch TVs can be had for $500.00 maybe less since 85 is becoming the new standard. The cheaper ones are the ROKU or other smart TV options but you don't have to let them be smart just don't connect them to the internet. I use them as computer monitors and let the computer handle the smart part.
It is 720P. I am not missing out on regular broadcasting
and cable channels. 1024 and higher internet video gets chopped somewhat, but I don’t care.