First of all let me start of by saying that if anyone promises you website submission to the search engines or charges you for it then follow this link to see how easy it is to do it yourself.
Secondly if someone promises you submission to 400 search engines then by following that link I can promise you the same. There are only 5 search engines you need to think about and they are Google, Yahoo, MSN (Bing), AOL and Ask. Nearly every other search engine uses one of these 5 for their results!!! In fact those 5 search engines also crawl each other so by being listed in one you are bound to be eventually listed in them all.
Thirdly submitting your site to any search engine is not necessary once you have other sites linking to you. When Google crawls the web it will follow the links and find you anyway. By submitting your site you simply tell Google you exist and what do you expect it to do with you if it can't find other sites linking to you. Certainly it won't consider your site very important and give your site a high ranking.