2022 BRN Discussion, page-2918

I am not an accountant, but think I am not bad with numbers.

Assuming your tax rate is 30%, and you have made 15 cents profit per share (buy $1.50 and sell $1.65).
Tax is 30% of 15 cents profit = $0.045 per share.
That is, out of your 15 cents profit, 4.5 cents needs to be paid in tax.
If you sold at $1.65, buying the same share back at anything under $1.60 ($1.65 - tax 4.5 cents) will cover the tax component.

Assuming a profit of $1.70 per share at 30% tax = $0.51 tax per share.
If you sold at $1.80, you can buy it back at anything under $1.29 ($1.80-$0.51 in tax per share) to cover the tax component.

Hope that helps.