As Christians we do not pay anything, salvation is free but we can give in order to help the work of salvation. So when the Lord Jesus Christ assumed the office of the high priest, He will continue ever, He has a perpetual priesthood.
The reasons why those priests in Israel were changed because they were not allowed to continue by reason of death, even Moses,Aaron and other priests during the time of the Levites being the priests of Israel.
Hebrews 7:23-
"And they truly were many priests, because they were not suffered to continue by reason of death"
Hebrews 7:24-
"But this man, because he continueth ever, hath an unchangeable priesthood."
Hebrews 7:12-
"For the priesthood being changed, there is made of necessity a change also of the law."
So the law with the Levite priests goes with the change, there is now another law under the priesthood of the Lord Jesus Christ. To sustain the law of salvation, we do not need to collect ten percent.
Il Corinthians 9:7-
"Every man according as he purposeth in his heart, so let him give; not grudgingly, or of necessity: for God loveth a cheerful giver."
God loves a cheerful giver and trusts the heart of a real Christian, of a believing Christian. God gave them the liberty to decide in their hearts the amount to give. So it us the biblical way of helping the work of salvation, not by paying paying tithes but be a cheerful giver.
Il Corinthians 8:1-
"Moreover, brethren, we do you to wit of the grace of God bestowed on the churches of Macedonia"
Il Corinthians 8:2-
"How that in a great trial of affliction the abundance of their joy and their deep poverty abounded unto the riches of their liberality."
Il Corinthians 8:3-
"For to their power, I bear record, yea, and beyond their power they were willing of themselves"
Il Corinthians 8:4-
"Praying us with much entreaty that we would receive the gift, and take upon us the fellowship of the ministering to the saints."
Il Corinthians 8:5-
"And this they did, not as we hoped, but first gave their own selves to the Lord, and unto us by the will of God."
This is the way the Macedonians helped the work of salvation.