Hey guys, this is my first time here, and I figured I'd get into bitcoin. Especially now, since the price is dropping, but it is a great long-term investment since it's the future of decentralized, untracked cash. So if I get some stuff wrong please correct me.
Bitcoin is a great investment period.
To say it's untracked however is not correct. Transactions are 100% tracked, recorded, and PUBLIC on the blockchain. Bitcoin is not completely anonymous. With enough investigation it is possible to track the owner of a wallet address. This is one reason why it is critical to never re-use the same receiving address(however for some business purposes I may sometimes use the same address for ease of accounting). If you are jumping into this I highly recommend doing a ton of research. There are tactics that you can use to help protect your privacy but due diligence is a must.
A couple of good resources are:
https://www.lopp.net/https://bitcoin.orgI also think you are asking too much for a iMac of that age by quite a bit. Take a look at eBay prices on those. You are obviously free to ask whatever you'd like but being as you are new and asking above market value you are likely to be dismissed by most people immediately.
Best of luck with your sale and welcome to Bitcoin!