You are probably correct about the long-term value of low-end scopes. Any low-dollar scopes that I have owned came with purchased guns. Two were Leapers scopes, and one was a Millett. However, none of these saw any extended use from me due to the fact that I never owned them for long after the guns were purchased. While I did not have any problems in the time that they were on my weapons, I could not attest to their long-term quality.
Although it would be nice if everyone could go out and buy a Mark 4 when they wanted a scope, this is not usually the case (I definitley know it's not for me, and I'm a Leupold dealer!!).
However, a happy middle ground is usually attainable, which is the reason I gave Nikon a plug in the prior post. I would definitely spend $200-300 for a Nikon instead of $150 for a Leapers or Tasco. The extra money is very well-spent, and you can get a great scope that doesn't set you back $1000. Take a look at this link; I think you will have a hard time finding a better scope for the money: