A reasonably priced scope with repeatable reliable turrets

Way too vague. What kind of scope are you looking for? Springer rated, PCP. ? Variable power, fixed? Etc ….



Also, I have learned VERY, VERY quickly about using any financial descriptive words on the Optics section ! One person's affordable is another person's used car purchase. I used to buy the best glass. Because the difference between it and mid grade glass was HUGE. The past ten years has closed the gap tremendously. See Discovery and Athlon for two examples. Way more than with the actual airguns. optic "enthusiasts", often mislabeled "snobs" , is RAMPANT !!!

I carried my new Athlon scope over to my buddies house this week. We compared it with probably 10 different scopes on some of his guns. There were four of us there. NONE of us thought the lowly Athlon scope was bettered by any scope we compared it to. And a couple of his were $800 to $1000 scopes. Our eyes just were not capable of seeing the differences worth spending an extra cent. I left with several people looking up Athlon and Discovery, and murmuring about selling their expensive scopes for Xmas funds. 

Smart men as far as I am concerned, JMO.

Anyway, if for a PCP, I would look at a Simmons Predator Quest scope. Can be had for $150, and compares with well with Bob's huge array of different scopes. I have been using one for years, and it is so repeatable, I have a scope knob on it, which I use to track vertically from 15 to 140 yds, PERFECTLY repeatable. So it boils down to what YOU need to spend to feel comfortable about your purchase. You can spend more on ANY scope, but you won't shoot any better. You will just be spending more.
 
Look at the vortex diamondback tactical line. They offer two models that are ffp one is 4-16 x 44 and has parallax down to 20 yds. The other models is a 6-24 x 50 and has parallax that goes down to 10 yds. Again they are both first focal plane scopes and have solid turrets that are not mushy plus the best warranty in the business. You should be able to find them for $450 or less.
 
I agree with Mendopellet that reasonable can be a very different term for different people.

I only own two airgun scopes, both scopes are in the mid price range which was “reasonable” for me. The scopes are an Optisan EVX 4-16x44 F1 and an Athlon Midas Tac 4-16x44 

They are both FFP and I dial for elevation so I’ve used the turrets a fair amount. They both track very well and return to zero. The glass and reticle are very good on both scopes and I highly recommend them.
 
Look at the vortex diamondback tactical line. They offer two models that are ffp one is 4-16 x 44 and has parallax down to 20 yds. The other models is a 6-24 x 50 and has parallax that goes down to 10 yds. Again they are both first focal plane scopes and have solid turrets that are not mushy plus the best warranty in the business. You should be able to find them for $450 or less.

I agree. If this is what affordable is considered to you then I don’t think you’ll be disappointed. Cabela’s has the 16x for 350 and 24x for 400$ I believe. I have 2 of the 16x and plan to buy some more in the 24x for my powderburners. 
 
I just bought an Athlon Helos FFP not cheap $450. Plan to put it on a Red Wolf HP There are a lot of positive comments on the vortex black diamond scopes .I happen to prefer the Nikon x1000 black. Similar money I thought the exit pupil eye relief better on the Nikon. Might be a ford Chevy situation.

One of the things that confuses the issue on scopes is the marketing. Every one if the manufactures has several families of scopes. Nikon has buck master and monarch black etc. I find it confusing and it clearly does make a difference. In some cases a huge difference . 

One of the most important things is how the scope is going to be used. It's nice to have the best but for what most of us do with air rifles I believe compromising some on the scope is probably the place to compromise . 
 
If $450 is "affordable" to you OP, I can probably give you 30 suggestions in that price bracket. I call that the HIGH end of the mid priced scopes. And it is flooded with good scopes that over achieve.

Affordable fall under $225 in my book. And I know a lot of GREAT scopes at that price. Right now, you can get a $419 Athlon scope for $189 shipped from a particular online seller. THAT is the best scope deal I know of, by a long shot. 

Just do the math for the percentage off, and show me how to beat it for a scope that equals a Vari X III Leupold for optical quality, side by side, to my eyes, and three other VERY experienced airgun friends. It just depends on what you WANT to spend to feel comfortable.
 
400 to 500 range I would be happy. 

Ton of options Two critical considerations How close do you want to be able to use the scope and then first or second focal plane . If you need or want it to parallex down to 10 meters that will cut into your selection . Then the type or style of reticle I don't shoot many of my guns closer then about 20 yards so most any "good" scope will work. I might not be about to shoot a 6 to 20 scope at 20 yards on 20 power but that's ok vortex Nikon Leopold Athlon bunch of them MTC Hawkeye


 
I agree with Mendopellet that reasonable can be a very different term for different people.

I only own two airgun scopes, both scopes are in the mid price range which was “reasonable” for me. The scopes are an Optisan EVX 4-16x44 F1 and an Athlon Midas Tac 4-16x44 

They are both FFP and I dial for elevation so I’ve used the turrets a fair amount. They both track very well and return to zero. The glass and reticle are very good on both scopes and I highly recommend them.

I have both of these scopes as well and couldn't agree with you more.