If bitcoin didnt have market value before July 2010, what does this mean? How could people buy it if it didnt have any market value then other than p2p, otc, and mining?
Just the way it is right now. We can see bitcoin price at $118k per bitcoin which means people are actually willing to pay $118k for just one bitcoin.
Back then the valuation was very less but it worked on the same principle and people were willing to buy and sell bitcoin for some price.
Although the exchanges were not present at that time but bitcoin's underlying principle of peer to peer exchange was still there.
So people exchange bitcoins for something else and thus the valuation continued to rise until today.