The first step is to understand what this industry is all about. Pricing mechanisms vary. Some sites give the papers away but require you to register and often, to submit at least one paper. Some sites charge a membership fee for subsequent access. Some sellers put a cap on the maximum cost.
Some sites have rather high additional charges for sending the paper electronically.
The papers are not necessarily recent, either. I analyzed the catalog based on a random sample of 9 categories that contained about 560 paper titles, date written, number of pages, and price. About three-fourths of the papers were under ten pages. Excluding one category specifically for 1998 papers, there were no papers written after 1994 in my sample. About half were written before 1982 and three-fourths before 1988.