I looked at PBase a while back but was never satisfied with it. They strip the ICC profiles out of the thumbnail images, so if your viewers look at the image in anything other than "original" size, the color rendition will possibly be off (particularly if they are using Safari). I did not see where it was worth it to pay for that. Also just from casual browsing experience I find their servers to be a little slow. Maybe it's just geographical realities between their servers and my computer, but I think other sites perform better.
I admit I stumbled upon a great alternative because I am a student and have free webspace offered to me via my university. But I found it dead easy to generate a gallery in LR (I'm sure Aperture does this too) and have it automatically uploaded to the web. I just use the standard lightroom HTML preset. It gives me an IMO very clean look with an image quality I can control. No flash or anything too gaudy, just a clean fast HTML interface.
Anyway, I don't know the specifics but I think that buying your own webspace somewhere and simply generating your own gallery via a program like LR or Aperture, probably is cost competitive with a hosting site, and gives you the most control over your image quality/presentation.
I will say too though that I don't sell any of my work. I have my pictures on my webspace just so myself and family/friends can view them easier than if I were to email everyone pictures, etc. I'm sure if I wanted to set up some kind of online store, that I would probably need to change it up.
Ruahrc
P.S. I had a brief discussion about this with someone I know recently, they told me that if you upload things to Google, that somewhere in their TOS is a clause saying that they are allowed to use any photo that is uploaded to their site if they want. I'm not sure if it's actually true, but if so that would be a personal detriment to using it. I'd be interested to know if anyone has compiled that kind of data, if places like Google or Flickr or Smugmug have any of those types of wording in their TOS indicating that you may be giving up at least some of the rights to the photo by uploading it to their servers.