Ram usage - how much is too much?

Hello all,
First I want to thank this community for existing. The developers, and the helpful people. I've been able to create a server I really cherish with what I've found here.

Anyway. I am renting a 1024meg server from mymcserv.com and so far things are running pretty well. I have a lot of plugins but I wonder if I have gone overboard:
BetterShop, BorderGuardLite, Essentials(all of them), HeroBounty, HeroChat, HeroicDeath, Permissions, RepairShop, Vanish, WorldEdit/Guard, WarpGate, iConomy.

While things are running fine now, I am concerned by the notice that "player x left, Freed 280.x MB RAM". Yipes. I've had as many as 6 people on at once and it seemed to run fine, but I would like to think I could host at least 10. Are these numbers accurate? Do they matter? Are they normal? What would be the best way to lower them if it's even important? (i.e. which of the plugins I listed are the biggest memory hogs?)

Thanks. And if you have any suggestions for running alternate versions of these plugins that you know use less resources, I'd love the recommendation.

 

I'm seeing around 80 MB freed when I leave from my test server. Though it has over 25 plugins, so I don't know if that's even helpful info...

 

the amount freed i have found is usually dependent on how long you have been on there. I've seen as low as .15M freed when im on for short periods of time

 

General rule - about 100mb per player.

 

How do you decrease the amount of mb per player?

 

use this as your start line

Code:

java -server -Xmx2G -XX:+UseConcMarkSweepGC -XX:+UseParNewGC
-XX:ParallelGCThreads=3 -XX:+CMSParallelRemarkEnabled  -XX:+DisableExplicitGC
-XX:MaxGCPauseMillis=500 -XX:SurvivorRatio=16  -XX:TargetSurvivorRatio=90
 -jar [path to craftbukkit] nogui

with this i do not have any ram recycled when leaving, it is done as you go along, this is not my code but it works.