Replacement windows are manufactured by thousands of companies. There are individual frame designs, features and quality. Some are made to last and others - made to sell. A replacement window installer or his salesman may try to sell the consumer an expensive replacement with extras he doesn't want. Such as an internal blind or louver and argon gas which prevents condensation, but eventually leaks out.

On the other end, there are plenty of vendors selling low quality windows that will leave the consumer with popped springs, broken seals and frames that allow windows to pop out with minimal stress.  Not for security minded individuals. For example, the $99.00 (dollar) American Standard replacement window sold by Home Depo may not be the way to go.  Further, a home improvement salesman may try to sell you a cheap window for a higher price with a good pitch. 

Having been a remodeling contractor for decades, I always advice the consumer to do some homework before making the call.  In this case, make a list of several window sizes you want to replace, research local manufacturers and then visit them for price quotes.  Ask questions and request to see samples of the finished product. This is what I do as a contractor, so I can offer the best price and quality to my valued customers. I would not deal with out of area manufacturers if possible, simply because I could not see the work before purchasing.