Cripes.  My wife sometimes calls me "Mr Doom and Gloom".  But I fit right in here!   

If you are not going to be exclusive elsewhere (what woudn't do much sense, in my opinion), why not? Istock pays less to independents, but sells image sizes at an higher price point. Maybe you'll get the odd 0.08 dollars sale, I don't know, but you will also get 3 or more dollars for big sizes. At many other subs sites, you'll just see subs, yes, 25 or 30 c, but for all your sales, small, big and superbig. Istock has the subs sites thinkstock, but you can opt out. And redarging the subscripcions at istock, you can get, as I'm got 35 dolar for a small... as odd as the 0.8 c, but real. Besides that, istocki s one of th agencies that sell more, probably number two in quantity and one in money.
That said, don't dream in instant money, not at istock not elsewhere. It is true that you are a bit late. To get a decent income will take you some time.

I have been doing stock for 4 months or so and do submit to istock.  I basically use up the 18 per week allowance by submitting 3 a day, which takes about 5 minutes and means you build up a portfolio slowly (50-60% acceptance rate for me).  Once I passed 100 or so in my portfolio sales become more regular (1-2 per week, so not loads).

As a relative newbie to stock, I would say yes, it is worth joining but don't rely on istock for a lot of income unless you go exclusive (which takes time- you need ?250 downloads).  Saying that I have had more extended license sales there than elsewhere.

I definitely recommend shutterstock-  they have very tough selection criteria and getting accepted is tricky but once you're in you will develop fast- the 3 day review times and unlimited uploads are advantages and you will learn what does well.  Since developing my portfolio there, I have done a lot better on other sites- it is like being on a training course in itself.

Good luck
Another Tom :-)

Once again great comments across the board. I have been very conservative on my camera equipment with a simple Rebel T2i and a fair lens 17-55 IS F/2.8 with basic lighting equipment - my total investment has been around 3k which includes CS5 (Student Edition). I have friends that make the same money as I do in the federal govt that have spent over 20K on their high end Canon Mark III or IV and they leave the camera in Auto mode - basically  point and shoot mode but just want to look good while taking photos. I feel that lighting, composition and being creative is more important than going out and buying a ton of high end camera stuff. Let's face it if all you had to do was go out and get a Mark IV to make 60K a year in this business we all would run out and get that Mark IV.

In the last six months I have learn so much from sites like this one and taking courses to include CS5, camera raw and photography. I am going to take a lighting course this week and looking forward to shooting even better. It would be funny to make some good coin on just using a Rebel Canon. Kind of reminds me of my fishing days- I had a small tackle box with only 2 silver spoons and a few spinners and yet I could out fish the big shots that can in from the cities with thousands of dollars of Orvis equipment. They use to follow me when fishing because I could read the water, know exactly where to place my lure and how fast to retrieve it. I would come home with dinner almost every time! Now I must admit that my Grandfather taught me everything thus telling me that I didn't need a fancy pole or other things - He told me that I have to have the Passion and Desire that would lead to success. That included going out on the worst days in storms to nail the smart (large) trout while 90% of the other fishermen stayed home. My Grandfather was a master!

Thank you all for being so honest and right to the point. If I don't reach my goal no biggie but at least I will know how to take good photos and have fun which my day job doesn't provide LOL!

Tom

The Rebel T2i is great for stock.  I really think good quality lenses are more important than an expensive camera.  If I was just starting out now, I wouldn't bother with photoshop.  The Gimp is free and does everything I would need for stock.  I still use Photoshop elements and a few free add ons.  That has saved me a lot of money that I spent on better quality lenses.