Hardmods aren't like modchips or anything; they're just a direct hookup of the NAND to an adapter (because the NAND is basically an embedded SD card) which allows for dumping it externally.
Since there's no exploits set up for 1.0 to allow such a dump in software, a hardmod is basically needed for this (alongside its added safety for experimentation).
Whether someone covers the cost is unknown, at least on my end. Not sure there's really a huge demand for 1.0 dumps aside from people who say these things.
Technically, you don't go to 2.X to
install A9LH, but to get a value from the OTP, which was patched for good in 3.0 (and why people downgrade).
After getting the OTP, you'd need to compile/get someone to compile A9LH and run it from probably 9.2 to actually install it.
A9LH is ARM9 control at boot, earlier than even MenuHax.
This allows for a fix to the N3DS 3D bug (irrelevant here), faster boot times, a 100% boot rate, the ability to use a hax'd environment without EmuNAND (though it's recommended to have of 9.2 if this is done) and potential brick protection (as you can basically always restore so long as FIRM0/1 are safe). Also, it's new tech and thus having it makes you