#ampere gpus

I had a question that revolved the RTX 3000 Series (in terms of the EVGA RTX 3080/3090 Ti FTW3 Ultra Gaming) how much should I be paying for used GPUs? Is $900 & $1,200 a realistic price for both of these GPUs? Or should I look into lower prices like $700/$750 for the RTX 3080 Ti (EVGA) and...