If RHX for whatever reason has to close the server somday (let's hope not soon!), I may consider renting a high-speed server to accomodate people from parts of the world who ordinarily are more lag-sensitive. Alternately if I get my optifibre (seems to be soon! 50mbit up and down) I may host it on an old PC (that's still a quadcore with 12GB) myself. I'm afraid though that in the current setting, people not somewhat centralized in Europe or with a fast connection from the USA will suffer lag on most MC servers which don't cost 500-1000 dollar/euro/diamonds/notches a year. It's the current state of online hosting services.
ooor, do it my way... my puny 16mbit/896k link can sustain 7-8 remote players without unplayable lags. The pc i run it on is a C2D E7500 with 6 gigs of ram.
cost of the link? 45€ per month, and something minor in electricity. the server itself barely draws 30 watts.
btw, minecraft is primarly a single-threaded app. its extremely heavy on the RAM use, but relatively light on CPU.
and i think there might be bug with craftbukkit RB1000 and its memory management. every time someone went exploring, we ended up with a laggy-like-**** server, complete with ram usage spikes, leaving the machine in deaththroes with only like a 100-ish MB of RAM free...