Until all are equally poor? Then where would there any longer be provision for those truly in need? Ah, yes.. the government. The entity that is allowed to violate the 8th commandment and steal from its citizens at the point of a gun. That isn't an exaggeration. If one doesn't pay their taxes to the government, they can expect government employees with guns to show up.
Giving should be done with a good heart. It is the only way it is acceptable to the Lord. Each person must decide what that amount of money, property, etc that entails.
And only livestock, grain, etc? Not hardly. In Acts, you had people selling all they owned and giving the proceeds to the congregation and the apostles. But there is no mandate that it must be done. It wasn't that Ananias and Sapphira (Acts 5:1-11) were in deep trouble for not giving the entire proceeds from the sale of their property to the Lord, it was that they held back some of it after they had said it was the all the money they got from that property. They lied to the Holy Spirit, that is what got them in trouble.
Me personally, I have found that whatever I give with the desire to serve the Lord, He always seem to make it so that I always have what I need. Not what I may want, but what I need. I was motivated by a true story of a guy that would increase his giving and the Lord always made up for what he gave. He gradually got to where he was giving around 90% of what he made, and still was living at the same level he did when he was giving just 10%. Every time he increased his level of giving, his financial situation improved to make up for it. It is to the point where he has paid enough to establish many medical facilities for missions work in many countries and heavily supported missions work.
Not saying in any way that this will be the same with anyone else, including myself, but I have found it to be somewhat true in my life. Once I started making a commitment of faithfulness to give at a certain level, I have found the Lord has made it so that my financial situation has not suffered because of it. I am now needing to consider to making a larger commitment of giving out of faithfulness. Not for what I gain, but that the Lord will always meet my needs as I grow in my giving back to Him. Trusting in His provision. Each person must evaluate their relationship with the Lord and come to their own determination what level they should be giving back. Not out of some legalistic observance thing, but cheerfully giving out of loyalty and faithfulness to the Lord.
I loathe those that put some sort of guilt trip in people about giving, especially with ulterior motives of lining their own pockets or expanding their religious empires.