I use something else, but I use topical skin products in conjunction with cellular nutrition. I think if you rely entirely on topical products of any type, you can't expect major results without nourishing the skin from the inside as well. You also want to find out if they are making their own products (either doing the manufacturing themselves or at least directly supervising it in an outside facility, vs. just slapping their label on someone else's product that you can buy under other labels).
To evaluate a product sold through sales reps, you can check on their Chief Scientific Officer and how that person rated in the ExecRank survey of last year. CSOs were rated based on their reliance on research and clinical data, their integrity, and other factors. To evaluate a company, go to the Direct Selling Association website and see if they are members. The DSA is an invitation-only watchdog group for network marketing companies. Before a company is invited in, the DSA spends at least a year reviewing the company's books, checking on openness and integrity, reviews the compensation plan for distributors, and even interviews distributors to see how they are treated by the company. So a company that makes big promises to new distributors but then funnels all the profits up to the long-time distributors or the company executives will be weeded out. The DSA looks at start-up costs as well as initial and ongoing training (and whether it's paid for by the distributor or given for free).
All of those factors help determine whether the price of the product is based on research, decent compensation of the distributor/rep, and whether there is too much profit going up the line to management.
If the cost is due to research and patents, that's one thing. If it's just to make you feel that you're getting a better product and all the money is going up to the company executives, that's another.