Is a JR Pass worth it for me?

We will be in Tokyo for 5 days, then taking the train to Kyoto for four days, and then back to Tokyo for three more days.
I can't justify the JR Pass even though the trip to Kyoto and back looks like it will be around 275USD.
I cant seem to find any info that says how much the average train fare is. And I'm not sure whether we will use more subway or more train during our trip. We are planning to visit Akihabara, Shinjuku, Ueno, Shibuya, and Asakusa, but if each train ride costs $15USD then maybe the Pass would be worth it.
Also, how much would be a realistic amount to put on a Suica card? This depends on how much a ride from Tokyo station to Ueno would cost (as an example, since I have no idea how much that would be). We would be staying at Backpacker K's Tokyo for the first five days and I'd really rather just put a chunk on the Suica that will cover subway/train rides without having to refill it over and over.
Any tips, ideas, thoughts on what I should/could do in this regards?
Thanks in advance!!

A 7-day Japan Rail Pass pays off for a round trip Tokyo-Kyoto. But you can travel cheaper by night bus, which also lets you save on hotels. Here are all your options:
http://www.japan-guide.com/e/e2363.html

try www.hyperdia.com and check how much it cost you to trave lfrom here to and to..you can use your JR pass while in Kyoto to go to Osaka for a few hours (Osaka is 15- 40 minutes away depending on the trains) or to Nara .or Kobe or..back in Tokyo you can use it on the last 3 days either on the Yamanote loop line or to go to Yokohama, Kamakura etc.

First of all, you mentioned "15$ for each trainride"? The longest distance to travel on Yamanote is from Shinjuku to Akihabara, and that is 180Yen oneway (aprox. 1.75$ i think) getting a suica seems like the best choice, and since you're only there for a limited amount of time, 2000-2500 Yen should be more than enough if you plan a little ahead. (like when you're in Akihabara, go to Ueno the same day, as its only 2 stops from there)

Have a good trip

Thank you for posting the website Hyperdia! I don't know *what* website I used previously but was horrified thinking that a short ride would be so expensive.
Would the JR East pass be usable in Kyoto to get around town (or the Suica?)?

the Suica can only be used in Kyoto on JR trains but the easiest way around Kyoto is subways for downtown and buses for many temples and gardens. A day pass for buses cost yen 500 per day. The subway isn't too expensive. Check www.urbanrail.net then click on Asia then on Kyoto, Osaka, Tokyo etc. on the Japan map. You can also check transportation in the A-Z section at the very top of every page on this Japan-guide site..