Nehemiah 2:20 So I answered them, and said to them, “The God of heaven Himself will prosper us; therefore we His servants will arise and build, but you have no heritage or right or memorial in Jerusalem.”

When God decided to do something, He begin to stir the heart of men towards the same. When it's time to build, it is not about how much you can give, your heart being involved. Your lack won't matter at the end of the day if the heart is connected. The reason is, God can use anyone to achieve anything when the heart is involved. 

I Kings 8:18 But the Lord said to my father David, ‘Whereas it was in your heart to build a temple for My name, you did well that it was in your heart.

It is a good thing to build unto the Lord, God desires it and prosper His people for such. The most important thing is the heart, God will work with anyone whose heart stays on Him. When it's time to build, don't shrink back, partner with God, you will be amazed at His favour you'll see. 

2Samuel 24:24 Then the king said to Araunah, “No, but I will surely buy it from you for a price; nor will I offer burnt offerings to the Lord my God with that which costs me nothing.” So David bought the threshing floor and the oxen for fifty shekels of silver.

Sacrifice cost, David knew this and said "He will not give the Lord what will not cost him". The beautiful thing about God is that, He does not use people and abandon them, as long as they are walking with Him, obeying His commands. The moment you start seeking His Kingdom first with the whole of your heart, other things will be added to you. 

It's time to buy and build unto the Lord.