2DExtremeProductions wrote:

I understand those but isnt that what im asking for? What specs are needed to run a BYOND world with a good amount of players on it with none or relatively low amount of lag.

That's the problem that I tried to explain (and obviously failed) earlier on. You are the only one with access to the source code and profiler, so you are the only one that could possibly know the answer. There is no common standard for resource usage on BYOND games, because there is no such thing as a common game (unless you count the game with the most modifications as standard, in which case figures are going to look rather bad, because these happen to be within the worst performing games, thanks to their creator's inherit lack of fundamental knowledge).
You are going the right way by wanting to spend the least for best results, but you're under the wrong assumption that every action/RPG game with x players would score the same results (which is not your fault, but a common misunderstanding around BYOND).

BYOND user X telling you that her game Y needs resource Z is going to do you no good, unless you want to host specific game Y.

If you want an advice, then create your game and hire Kuraudo (cheap, yet reliable and experienced) to look through your finished work. He'll likely tell you a lot of points where you can seriously save yourself trouble and a couple of points where you're massively wasting resources.
After adjusting your game accordingly, talk to Airjoe and find a server that fits your need. The benefit is that he knows what he's talking about and he is nice enough to find a deal that suits your need by trial and error if the need arises (which it shouldn't as Kuraudo could likely provide figures after having studied your source code).

That might sound like you're going to waste money, but in the long term, you're not only going to actually save, but even learn and provide your customers with a more pleasant experience.

Confucius says, replying to wrong post like talking to wall.
The person you should have replied to was the original poster, though you do not really contribute much to the topic that wasn't elaborated before.
On a related note, it isn't exactly bad to be willing and try to push the limits, so the goal of 300 players is, through unrealistic, still desirable.
Personally, I wouldn't use Slicehost for such a task, given that you'd have to pay 100$ a month for 900 GB monthly transfer, whereas I'd get 1000 GB monthly transfer for 11 $ on a provider suggested above in this thread.

2DExtremeProductions wrote:

(...)in the end its really all about your code.

There are certainly more factors to that.
You're right that optimising can make or break your effort on hosting a game, but there are some points around BYOND games that you can hardly tweak on. This leaves you with needing a decent amount of bandwidth for example. And even if you could adjust the networking protocol, you'd still have the carriers/peers/location of your server influence response times to clients.