Look around for the first generation di2 hydro shifters - rs785 - pair with a grx or long cage di2 mech. depending on frame you can probably get calipers for 120ish. as @hippy said, waiting for parts to show up over time is cheaper - otherwise things like junction boxes and batteries eat up a lot of the budget. also, some good deals to be had on etap axs - with just shifters and 1 rear mech it might be cheaper - i believe you can swap out the jockey wheels to run a non-flattop chain and cassette (and avoid the expense of a freehub).
Look around for the first generation di2 hydro shifters - rs785 - pair with a grx or long cage di2 mech. depending on frame you can probably get calipers for 120ish. as @hippy said, waiting for parts to show up over time is cheaper - otherwise things like junction boxes and batteries eat up a lot of the budget. also, some good deals to be had on etap axs - with just shifters and 1 rear mech it might be cheaper - i believe you can swap out the jockey wheels to run a non-flattop chain and cassette (and avoid the expense of a freehub).