Cheapest option to buy BTC when buying at irregular intervals, using USD from bank account? And how do I minimize/consolidate UTXOs? And advice on hardware wallet. And selling at a loss for taxes.

Hello, I was going to use Swan Bitcoin to buy BTC, but they're very limiting in how much USD I can spend daily.

What's the cheapest option for me (I'm in the USA) if I want to buy BTC in amounts of $1,000, $10,000, or more?

I might do DCA of a few hundred weakly/monthly, but... I want the freedom to buy in large amounts whenever he price of BTC drops, I want to buy using money in my bank account, and I want to be able to transfer the BTC to a hardware wallet for cold storage.

I'd also like to know how much keep track of the price I paid for specific BTC, so I can sell at a loss for taxes, then immediately buy back the same amount it the lower price.

I use a HP laptop, what's a good hardware and option, I don't want something requires NFC or smartphone. I was considering a Trezor Model One.

Thanks!

P.S.

I'm not a tech, crypto, or math guy... so I'd like a KISS answer.