draganm

had a malfunctioning DA 7900 10 speed right shifter for quite some time now2, would float between 2 of the gears like 5th and 6 cog down. New housing, new cable, new RD, no joy. Finally took the shifter apart last night and had what looked like pieces of metal washer fall out. No idea what it was since Shimano doesn't offer exploded diagrams of this part. Shifters are pretty old were used a lot, one of the 2 gear tracks , the one for up-shifting was worn down pretty bad compared to it's brother for down shifting, which would make sense as the load is much higher going up.

Tried ot re-assemble anyway after cleaning, which was a nightmare. After an hour hucked it all in the trash. This is off a 2013 full Carbon bike, but the shifters were probably 2010-11. I want get it back on the road and either ride iot or sell it. What should i buy, I've lost track of all the lates-doo-dads. Don't want to spend a fortune, the DA pair set me back $450.

I don't want Shimano back in there, since SRAM will require yet another new RD, but will if it's cheaper . Doesn't look cheaper, Shimano R8000 will set me back $500. with cassette.
Sram Rival new take-off for $200.-$300. with shifters , cassette, RD, and chain?

I don't care about weight, i want good function and durability. please let me know your experiences with any of this stuff (that you have used please)