It is possible to do a side-scroller for well under $500K, however it is very likely that a 'noob' would end up spending well over $1M (assuming one has the money!) by sheer lack of experience.

I suggest starting smaller: scale down on the amount of levels, reduce the amount of features, stick to straight 2D if possible, and try to learn and do as much as you can on your own.

The project probably won't be profitable even then, but the experience you'll earn from the effort will cost you much LESS than $500k, leaving your hypothetical super-mega-funding in your pockets for when you have more experience and can actually turn it into a successful project.

Perhaps you're right. I've been mulling over this particular project in my mind for a while now, and I really don't want to screw it up. I do have another idea that would take less money/manpower and I should start with that first.

a) to recoup the costs of the game must be expensive market analysis and very broad array of expensive advertising;

Not necessarily.

b) it is necessary to release the game for all popular game platforms;

Necessary? That's never necessary. You always need to take into account whether a port is valuable or not.

Because each port comes at a cost, you have to balance this against expected sales.

For example, on mobile, it is common trend to make an Android port, but assuming your game uses a demo/unlock app model, you'll find that your app will sell 3-4 times as much on Apple's Appstore than it will do through GooglePlay. With so few sales, it is ALWAYS worth the extra port? A number of developers forego that port for a reason, not just because they shun Android phones...

c) the game has to be thought out seriously for what it is, what the gamer audience, whether they are still in the world;

Not sure I'm following...

- so, seriously speaking, but usually designed game to move to the additional platform despicably low cost compared to the costs of new dressing .. and in this case is discovered a new niche to distribution ..

There's more to it:

What if you can get Xbox exclusivity for 6 months and cash in 500 000$?

How advisable is the playstation port then?

It is definately possible, to be honest I don't have too much expertise in this field, but I think -500k is quite realistic for a small scale game. I think the problem with most small budget games is that they try to cut costs everywhere. My advice is to not cut costs on people you hire (within reasonable amounts of course). In the end, you usually get what you pay for and hiring cheap employees or even students will likely leave you with sloppy code and artwork.

Anyway, good luck!

It is definately possible, to be honest I don't have too much expertise

How can you put "definately (sic) possible" and "I don't have too much expertise" in the same sentence?

Either you know, or you don't...

I think the problem with most small budget games is that they try to cut costs everywhere.

Most small games are made by very small teams, oftentimes by unpaid people. Most indie games end up bankrupt before release and decide to ship whatever they can in a hail Mary. Then again, most indies don't have anywhere close to 500K $ to spend...

In the end, you usually get what you pay for and hiring cheap employees or even students will likely leave you with sloppy code and artwork.

You'll probably end up with crap code and art even if you pay a lot unless you put a lot of thought into WHO you're going to "hire". Oftentimes, it is better to partner up with someone local and discuss specifics with them than send out an advert. What you need, as an indie, is (a) longterm reliable and motivated partner(s). Skills performing a single task may not be nearly as important as the ability to stick with the project and do more than is asked. If you can get your hands on someone that cares about the end product as much as you and is willing to do everything (that is, won't label himself as a programmer or artist but will actually help with more than one thing) to make it count, then you are lucky and whatever the game ends up costing is what it needed to cost.

Working with freelancers, alternatively, is also a good avenue.