Gravel Groupset Ideas 1x12

[MIMH]

I am looking for a 1x12 Gravel groupset with Electronic Shifting.  I am not convinced Wheeltop GeX or LTWOO eGR are fantastic from the reviews out there. They could probably use one more design cycle. They are not super cheap either.
But all SRAM or Shimano groupsets are well north of $1000, which seems overkill for my project.
So here is what I am thinking and I would like some feedback.

Magene P515 power meter crankset $299

SRAM Rival Shifter Brake $79 (https://bikecloset.com/product/sram-rival-axs-d1-right-side-f20-950mm-shifter-caliper-caliper-bolts-washers-not-included-oem/)
SRAM Rival Derailleur  $149 (https://bikecloset.com/product/sram-rival-etap-axs-d1-rear-derailleur-speed-12-black/)
This derailleur does not take a wide cassette so I would swap out the arm for a longer arm $52 on Aliexpress
I'd need to find a left Rival brake lever and piston only, don't need any shifting.  These are a bit hard to find in lever only, at least in the matching color it seems. I wonder is the actual lever is handed or if just the hoods are? Does anybody know? Hoods can be found online for $40 and the price for a shifter brake at $79 is cheap so I could just swap the hoods if that is the only thing...
The derailleur comes without battery so lets add another $15 for a AE battery

ZTTO cassette 11-50 $60

Totals to $775 (OK without chain and chainring) for an SRAM solution with a power meter, which I think is decent?

Not sure if all this is going to work though 

[raisinberry777]

You need both sides of shifters for SRAM electronic shifting. Left side goes up the cassette, right side goes down. There's only one button on each shifter.

[MIMH]

THX! That is great feedback, that's good to know. I thought the left shifter would operate the front derailleur (which I would not need), but that is not the case.? So these shifters work differently on a 1x than on a 2x setup?
So my plan doesn't quite work, I guess. I have a wired SRAM shifter now and that works differently, I guess. Interesting. I looked at quite a few reviews, but did not pick that up.

[raisinberry777]

THX! That is great feedback, that's good to know. I thought the left shifter would operate the front derailleur (which I would not need), but that is not the case.? So these shifters work differently on a 1x than on a 2x setup?
So my plan doesn't quite work, I guess. I have a wired SRAM shifter now and that works differently, I guess. Interesting. I looked at quite a few reviews, but did not pick that up.

Yes, for eTAP:
Left shifter - up the cassette
Right shifter - down the cassette
Both together - changes chainring

To be honest I'd just save your pennies, buy a set of Rival E1 shifters/brakes, then for the rear it depends on how low you need your gears to be (i.e. 10-52 and MTB gearing or 10-46 and gravel gearing).

[zegal]

Hey,

im using Eagle GX AXS derailleur on my 1x12 gravel - works perfect, and gives You more cassete options (10-52 for example)

Just be mindful of Chinese cassettes - i have three; ztto 9-50 and 10-44, and goldix 11-36, whilst they do work, they are noticeably louder, i am unable to eliminate unpleasant noise completely, when they are used i;m going back to the sram originals.

Rival brifters are great, if You want to cut the price even more You can look for Apex ASX - those are fine too, and there will be lot of them on used market from ppl replacing them for no reason on their new checkpoint SL5 bikes

[MIMH]

Good idea to use a GX ASX with RIVAL shifters. Just ordered the shifters from two different places, for whatever reason, they only had one hand in stock at 5-0+% discount:)
I'll look at a GX shifter to complete the system.!