The amount of time spent for searching a perfect match and money paid for contacts, memberships, and correspondence are just a part of what will depend on your choice.

The selection of a dating agency is an important ingredient in your search for a single Russian woman. The quantity of time that you can spend searching a perfect girl and money that you paid for contacts, correspondence or memberships are just a part of what will depend on your choice. 

Try to search some of these keywords in some important Search Engines: Russian brides or Dating Girls or Russian women? you'll see related search result pages. But you want to know which is the best agency option, that is the key question. You have the response, if you want to build your own relationship or if need help of a matchmaking agency. 

Take a look throughout the websites of the first page results of the search engine that you like to use; you will find several hits that are good, and if they are a successfully agency is because they are qualified company and your probability of success will be higher.
The benefit of important and successful dating agencies is that these agencies are able to have lots of single girls, and offer a wide range of options. Huger the database makes more difficult the task of keeping update the information. The emails of the girls are infrequently confirmed, with many ladies profiles posted are unavailable and most of the girls are never contacted personally. This is not always the agency fault, is women fault that forget to update when they met a man. Also, some dating services buy or hire emails from local agencies and make profits from the sales.

In bigger dating agencies you can find a big contest between single male in contacting girls. A girl can receive 50 or more emails per week, the majority of the girls not stay alone for long time, because they found their partner.
You have best opportunities if the girl is new in the agency (one or two months).

In consequence you will be capable to write to girls that are new and just started their exploration in the agemcy, and are not in relationship, so you will have more chances to contact her.

There are lot of entrepreneurs that found dating companies to earn some money, and when they don't earn a cent, they cancel the company leaving their clients with nobody.

Look for anti-scam. Check if the agency is listed in a anti-scam website or in anti-scam associations. 

If you frequently meet mentions to a dating site agency, this will be the indication that the website agency is good.