Tour Companies

It is easy to do a day trip - it will be a long day - on your own. What is attractive to you about these tour companies?

I think what I liked about tours is that they book the Eurostar trip for you...I had heard that its confusing to book your tickets.
Maybe someone could help me out as of what to do. I am traveling the last week in July with my grandson that is 15 and my daughter.

Have you already tried booking the train tickets, or do you assume it's confusing (without trying first)? It looks easy and straightforward. I don't know what the advantage of a tour company would be either, since most of the transport would be done by train and you can do the trip as a do-it-youself.

Explanation of system and how to book
https://www.seat61.com/London-to-Paris-by-train.htm#Fares
Official booking site
http://www.eurostar.com/us-en

It is just a train ticket so I don't know what is confusing. You do need to buy as early as you can since EStar follows the standard airline pricing pattern of increasing as you get closer to the departure date. Just get on the web site and do it.

There's nothing at all confusing about Eurostar Tickets:

http://www.eurostar.com

You definitely don't need to pay a tour company to book a ES ticket for you.

If you're traveling London to Paris then there is only 1 station to choose from in both of those cities. Choose your date, your time, select your level of comfort and be on your way.

Thank you for the great suggestions nice to have input from seasoned travelers.
I will be booking my tickets myself!

Great Answer!