9 speed drop bar inexpensive -
consider Shimano Sora
and / or Shimano Tiagra 10 speed
fair amount of Sora and Tiagra NOS and new/takeoff stuff avail (at reasonable prices)
Tiagra 10 speed will provide the option to go hydraulic disc if that’s your thing - but that could also bump the cost up and above ‘inexpensive’