The cheapest way to get satellite shifters is to go with SRAM if you are in the US.
House of Cogs on Ebay has Rival AXS Levers @ $300 per set
Bike Closet has D1 Force @ $320 per set
You can also pick up from Mikes Bikes:
Rival AXS RD $120
Rival AXS FD $90
Batteries: $47
Charger: $39
I think this should put you somewhere around $633-$660 + Tax for the shifting components.
With Force D1, you can use the Aliexpress sprint shifters, or with Rival, you can use the wireless blips. Its a bit more expensive than alloy EDS and on par with carbon EDS. With coupons, you are looking at spending an extra $100-$150. While you will need a new RD down the line the shifters are 13 spd compatible. This is probably worth it to many people over both Wheeltop and Ltwoo right now, given you can walk into a bike shop, and nearly any of them will help you warranty an SRAM part.
YMMV, but I broke an RD in a crash. I said I broke it in a crash. I have insurance that would have covered it, but SRAM insisted on a warranty exchange.
You do not need to use SRAM cassettes or chains if you don't want to, but I would as the Force / Red flat top chains are extremely economical at current prices (~$40), and they last a very long time with SRAM cassettes. You can just avoid the Rival chains.