I'm not sure that works universally. If you buy a bond with a 2% yield today that matures in 3 years and you decide to sell in 1 year instead and at that point the current rate is 3% the price you sell at will be lower than the price you paid so you won't make a 2% return in the first year...
Re: fees depends on your platform. Fidelity charges no fees or markups for treasuries but if your platform does it's something to consider in addition to bid/ask spread.
Re: fees depends on your platform. Fidelity charges no fees or markups for treasuries but if your platform does it's something to consider in addition to bid/ask spread.