Also take Internet speed into consideration!

So a 8gb server would hold

100 slots

Plus plugins like factions. different worlds. enconmy .the all those mob pvp arenas

Some '32GB ram' servers only have like 100 slots and only like 20 plugins and are still laggy. Either they're lieing, or you need to be careful about how many slots you use. I have 3.5GB and it runs fine for a 50 slot server. Depends on your speedtest.net speeds, I've acctually got really good ones.

I pay $5 a month for my server

When you use allot of intensive plugins CPU matters. You are best of with a super fast 3.5GHZ+ CPU. Don't bother with CPU's more than 2 cores, because minecraft only uses 1 core....

It can ran upto 200 slot depending on how plugins you, and how smooth the server runs.

If your paying $100 per month, get a better host. The minimum I think is like $8 per month

It also depends on your internet speed.
http://canihostaminecraftserver.com/
Use this, gives you the exact amount.

I can hold about 30-40 on a budget 4gb computer whilst playing, it doesn't have high processors and that but still. I reckon you will get around 70-100 at least. But as for keeping your server on I suggest either buying a dedicated server online OR buying a budget computer which can handle your server and its needs, and keep it on all day, or if you have a spare computer using that to play. But you should be able to just keep your computer on all day and that unless your family turns off their wifi at night for whatever reason (like my parents did before for a random reason). Also, why does everyone want to be staff, you need to choose friends and find people who join your server and are dedicated.

But that cost like $100 a month

When I could host it myself

No. Try buying a server online!

I'm not looking for staff right now

Is there a plugin that keeps ur server up when ur computers turned off

About 1-125 people and plugins. Are you interested in staff or admins? pm me I would like to be an admin on your server. And I do not grief hack or cheat

So lets say my

Server has craftbukkit factions economy all them

How much plugins + slots can a 8gb ram computer hold

im on ur server

8GB!?!? Around 1-125