As in all optics, it comes down to the dollars that the Retail company (Bushnell, Burris, BSA, Leupold, etc.) are willing to pay and what Quality level that they have in their contract with the Manufacturing facility. You really get what you pay for on the low end scopes. When you get to the mid-range scopes (say $150-300), most are really getting pretty close with a few standing out above the rest in comparing warranty, brightness, clarity to the edge. An example of that would be the Weaver Grand Slam. It gets great reviews and gets compared to some European scopes in brightness, yet is now made in a Meade (parent company) plant in China. There are a few good quality scopes coming out from China, but most coming from there are low end, low priced product which is not going to very good quality. Japan has 3 major facilities and all are capable of producing very good quality. Just depends upon the contract for the product.
Nikon has stepped their Buckmaster line(new line out now, not the pre-summer 2005 or earlier) with some new coatings that will get the light transmission up to 92%, same as their Monarch. Now it is gettting to be a toss-up on which to buy, Burris Fullfield II or Buckmaster in the 3-9x40 series
If you get into the lower priced scopes, stay with a brand that has that lifetime warranty. If you do your research you will find out the good and the bad about each line, I also look to see how much refurbished product is around due to the fact that if there is a lot of that product, I want to stay away from that stuff.
If you need to stay in the $50-100 range then look at the post-2004 Tasco (Bushnell now owns it but there is no warranty for anything that does not have BPO on the end label), Bushnell Banner and Trophy. $100-200 would be Bushnell Trophy, Legend and Nikon Buckmaster and Prostaff, Burris Fullfield II and Weaver Classic and V series and of course the Leupould VX-1(forget the Rifleman, entry level and no or little difference to the VX1 which is an updated Vari-XII). Over 200 I would look really hard at the Weaver Grand Slam (there have been comparisions in some hunting magazines between the Grand Slam and the Zeiss Conquest, field and stream or outdoor life I think).
This is to long but remember you get what you pay for.
Mark