nexsuica/metro card/Jr pass?

Hi I will be stopping in Tokyo for 4 days. I haven't bought a JR pass as it seems a bit expensive. I will be travelling from Narita Airport to TOkyo station there and back, go sightseeing round tokyo, go to Kamakura and Hakone. What is the best mode of transport or card to get do you think?
Many thanks! Lilly

--I will be travelling from Narita Airport to TOkyo station there and back, go sightseeing round tokyo, go to Kamakura and Hakone. What is the best mode of transport or card to get do you think?--

NRT to Central Tokyo: Suica and NEX for 3,500 yen
http://www.jreast.co.jp/e/suica-nex/index.html
http://gutereise09.blogspot.com/2008/07/narita-express-to-to...

Transport in Tokyo: Use the suica provided on the 'Suica and NEX' combo. When the credit runs out, just top up it in increments of 1,000 yen and more via the ticket machine. The computer in the turnstile automatically deduct the right fare when you clear the turnstile by placing the card on the machine after the trip.

Tokyo to Kamakura: Kamakura/Enoshima Excursion ticket by JR for 1,970 yen from any station on the Yamanote Line
http://www.jreast.co.jp/e/pass/kamakura_enoshima.html

Tokyo to Hakone: 2-day Hakone Free Pass for 5,000 yen from Shinjuku, preferably on the Odakyu limited express 'Romance Car'
http://www.odakyu.jp/english/freepass/hakone_01.html
http://www.odakyu.jp/english/rc/index.html

Odakyu Express train takes two hours from Shinjuku with a transfer at Odawara.

http://www.jorudan.co.jp/english/

Thanks a lot. It really helps! Can I also ask whether the fares you mentioned to Kamakura and Hakone include the return ticket or is it just a single?
Thanks again! Lilly

--Can I also ask whether the fares you mentioned to Kamakura and Hakone include the return ticket or is it just a single?--

Both include a return trip from Tokyo.
In case you take the limited express 'Romance Car' to get to Hakone, you need to pay a surcharge of 870 yen each way.

Happy travels.

Thank you so much! Lilly