I use GotoMmyPC for work, gives full remote access to my desktop PC, through a website.
I usually use it from my XP laptop at home, but I can also get onto it through a Android App on my tablet. Copes with everything, even my dual screen setup, just have to pan across and zoom in and out to see everything. Just like being in front of my computer, no problems with connections.
I also use Citrix to connect to another PC based at a customer office. Again, I can connect from a website, so access it anywhere. That one is a bit slow as it has to go through servers in Paris and Aberdeen.
No idea on costs of either though…