There's a lot of companies offering web-based IDEs with built-in terminals now. They've already started to differentiate themselves with unique features too! For example:

http://wakari.io/ - Focus: Scientific computing and analytics. They also offer a great implementation of IPython Notebook (really, the integration with Anaconda/conda is awesome). It's run by the folks at http://Continuum.io (Anaconda, conda, Numba, IOPro, Bokeh, etc).

http://www.devtable.com/ - A really slick (love the default dark theme) Web-based IDE. The GUI is really nice (minimal--the good kind) and doesn't "get in the way" like some of the competition. They also have lightning-quick deployment of your apps to GAE (the speed at which you can deploy/test your code impressed me). They also have an interesting LaTeX project option which also has instant deployment/testing. Useful because getting the LaTeX tools setup on a workstation can be a real pain (and they're SLOOOOOOW).

I've been using nitrous.io for a month or so. It looks like this is the same thing, except without the browser-based text editor, which I kinda like since I haven't gotten really used to working in any of the terminal text editors yet. It's not clear if they support real ssh access or sftp either.

I'm not sure how nitrous is expensive. I can't find any ways to give them money right now at all, or even any proposed future pricing. I have a few quibbles with their system, like the way their servers seem to shut down if not used for a couple of days, the ssh sessions disconnect semi-randomly, and no root access to install things that aren't already there, but cost doesn't seem to be an issue.

Yes we support SSH and SCP. Yes we also have browser based editor. Just need to go to the main site. We also give root etc. As long as your using the VM it will not shut off - however it will shutdown 15 mins after you logout.

I think you're looking for this: https://www.nitrous.io/pricing