hi im brand new to bitcoin and I only know the very basics of it. I have a few questions

1. as the title says im looking in ebay to buy bitcoins and there are some sellers are selling 5 bitcoins at opening of auctions for only 1 USD is it a scam I mean at the current exchange rate from my understanding 1 coin alone is valued at 900 USD which is a total value of 4500 USD is this a scam or is this legit I only ask this since should I place a bet and win for only like 10 USD the seller must be mad to take a massive loss like that
2. if it isn't a scam how does the seller deposit his coins into mine do I send him my wallet address
3. if I have to send him my address can he hack my wallet using my address or worse send my address to other hackers

sorry to seem like such a noob but I had just learned about bitcoin recently and like I said previously I don't know much about it basically any information I found from bitcoins's website summarizes m=the extent of my knowledge on bitcoins

I am brand new to bitcoin and I only know the very basics of it. I have a few questions:

1. As the title says I am looking in ebay to buy bitcoins and there are some sellers are selling 5 bitcoins at opening of auctions for only 1 USD is it a scam I mean at the current exchange rate from my understanding 1 coin alone is valued at 900 USD which is a total value of 4500 USD is this a scam or is this legit I only ask this since should I place a bet and win for only like 10 USD the seller must be mad to take a massive loss like that
2. if it isn't a scam how does the seller deposit his coins into mine do I send him my wallet address
3. if I have to send him my address can he hack my wallet using my address or worse send my address to other hackers

Sorry to seem like such a noob but I had just learned about bitcoin recently and like I said previously I don't know much about it basically any information I found from bitcoins's website summarizes m=the extent of my knowledge on bitcoins