You are asking what to put down to questions on the UK entry clearance form, and invariably the answer is taken from 'best practices': write down the correct answers. If the form calls for an explicit number like
What is the cost to you personally? You are in a position to know this figure and would write it down. If you do not know the figure, then your application may be misconceived and you should wait until you have the answers.
If the cost to you personally is 0, then put down 0. If you do not know the total cost of your trip, put down that you do not know or ask your uncle what the right figure is and then write it down.
Aunts and uncles do not qualify as close family. The part where you had to check 'other' because 'uncle' does not appear as a choice means that you were filling out a part of the form they told you to SKIP. This can be fixed by reading the guidance carefully.
Sometimes people have questions like yours because they are in reduced circumstances and believe giving the 'real' answers will have a negative impact on the decision. So they want to know what to put down for an answer instead of the 'real' answer, and this generally leads to refusals (per your previous question). They do not require a specific amount to appear in your bank account, you should put down the current balance or the balance from your most recent statement. Also, they do not refuse on lack of money where there is a valid and trustworthy sponsor.
Part 8 of the form is devoted to 3rd party sponsors. They are smart enough to look in that part of the form if it is filled out. If your uncle is offering to sponsor your visit, write it down. Then get your uncle to explain why he is doing that and to submit all of his documents on your behalf. If he does not own his house, he should additionally submit permission from the landlord for you to stay there. He should also write an undertaking to remain in the UK during the course of your visit. Expect your uncle's premise to be thoroughly challenged, so it needs to be well founded in order to succeed.
Between his evidence and your evidence there should be no gaps. If a given piece of evidence is missing, you can explain why.
Your discussion about being a student and how you are receiving support for that was somewhat unclear, but I gather your previous refusal mentioned that provenance of funds was an issue. It's a very common source of problems and there's lots of existing material here on the site discussing it...
These came from people with provenance of funds issues similar to yours. Please read them and see how well they can help you devise a better strategy for your next application. If not, you can then ask a really specific question that has not been covered previously.
Adding some General information about UK visit applications in Russia.
You will submit your application to a Visa Application Centre (a commercially outsourced station) and they will forward it to the regional hub in Moscow. Moscow is a great consulate with a success rate percentage in the high 90's. It means not very many people get refused. They have an enviable turn-around time. For your specific case, they have lots of experience in 3rd party sponsorship and will happily approve them in a few days when all of the stuff dovetails. As mentioned, they do not have that many refusals, and when they do it is passed to the higher ups for an additional review to make sure the refusal is justified.