Take a look at ADE RD3-006B greendot. From advanced optics. $89 with mounting plate to fit rear screw holes or factory rail. Works good on mine. Also get a bx trigger, use 10 rd mags and cci mini mags for reliable shooting
What's affordable and fits my purpose may not fit yours.
On my first project i landed on a Bushnell Trophy Xtreme 6-24x50
My 2020 Appleseed project rifle that turned into a bench rifle has a Vortex Strike Eagle 4-24x50 scope
I put together a lighter rifle that is somewhat "all purpose" and a Primary Arms 4-16x44 scope sits on that one. Great scope for under $200
I have a purpose built race rifle with a C-More railway red dot
Just put together another "all purpose" rifle with a Vortex Strike Eagle 3-18x44 scope on it.
Doing a other bench rifle right now that will probably get a Vortex 6-24x50 for target shooting
Also have my Copper Mica edition that my wife uses for plinking and it has a cheap Nikon prostaff rimfire II 4-12x40
When I pit my Man's Best Friend collectors edition back together, it'll probably get a red dot again. I had bought a Sig Romeo3 for it and it broke right away. Sig determined that it was a fake, so i just threw a cheap Vortex scope on it without adjustable parallax and just used it for plinking. Rifle became a donor for my blue laminate stock one pictured