Check the poverty guidelines on the USCIS website and it will give the $ for one person and more persons and the region you are living or going to live.
The fees also depends on if you do AOS or CP...
I will put up the things you need to know before entering the DV lottery and in there i have a few fees and things to know..., maybe that will help too.

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http://forums.immigration.com/showthread.php?t=302729
Things to know before entering the DV 2011!
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Before you enter into the DV 2011 when it opens to any eligible person, you should be aware of the following.
You don't get the GC just by winning. You have to show proof of certains things like:
-High School diploma or equivelant or having worked for the last 2 out of 5 years in a job from the approved list. (to be found on the DV website)
-Your country of origin has to be eligible to play the lotery.
-If ou have syphilis or HIV your chances are slim to none of obtaining the GC.
-You have to pay the DV fees after winning and before obtaining the GC and if you are denied you won't get a refund. (fees can be up to $ 1,600 per person)
-You pay for your own tickets to travel to the US after having the GC. Additonal tickets for people traveling with you, all for your own expense.
-If you don't have a job (job offer doesn't count, you need to work the job and have proof) in the US you either need to proof you have enough savings (according to the poverty guidelines) per person or you need to have a US sponsor who is willing to sign off to guarantee he/she will provide in case you won't have an income.
-Have no prior criminal record (counts for all applying ofor the GC), some things are over looked but being a felon is a guarantee you will be denied.
-You have to know if you really want to immigrate since the GC isn't just a visa on which you can live in your own country and go and visit whenever you want....of course you are allowed to travel in and out the USA as much as you want, but the GC means you live and work here the majority of the time.
Many people enter the lotery and don't realize that if you win, the only thing (but most important) is a chance to enter into the process of obtaining a GC which can take months and cost money and some stress but the great GC can be waiting in the end.
I didn't write this to discourage any one but just so people know what they enter and if they win they know they really want to move here...otherwise don't enter and give the people who really want to be here, a better chance of winning.
I have read so many threads from people who only started to think after winning and sometimes didn't have a chance to obtain the GC or didn't want to move....so please think before you enter!...and hopefully you win!
Medical cost can also add up. It depends if you already had all vaccinations taken care off or not. If not you have to pay to get everything updated and for all woman/girls between 12 and 26, they need to have the HPV vaccin which takes 7 months to complete and only if you are pregnant you don't need it otherwise it is mandatory. If your TB turns out to be unsure, the civil surgeon can order X-Rays to be taken which add also to the costs. For every person filled out on the application you have to have the medical done...(added this due to sudipmuk response). Medical fees vary from $ 100.- to $ 400.- but maybe some have paid even more per person. HPV cost aprox. $ 145.-.
Lately gay people who got married in Countries that do recognize gay marriages, have asked if they are eligible to apply together if one is winning and can the spouse apply too. The answer is very clear. "NO". The USA doesn't allow gay marriages. Even if they have kids and the kids will receive a GC it will take at least 5 years before the child can become a Citizen and can sponsor a parent, but not a parent from the samesex as the other parent since only a man and a woman can get a baby, so 2 men or 2 woman can't receive a child and be both the parents since sex marriages aren't recognized so neither will the adoption due to the marriage be able to be a way to obtain a GC.
If parents are divorced or separated and want to enter, they need an official paper stating they can take their child(ren) to the US.
If you claim your husband/wife died, you need a death certificate to proof.
If you have proof of all requirements you should be eligible.
When you move to the USA you are responsible for all costs of moving, tickets, housing, medical expenses (insurance) and future income. Unless you have some one paying for all of that, you have to pay it your self.
Many have done it before you so you should be able to do it....