Electricians

Hello! Think this will be my first actual post so hopefully I don't miss anything.

We recently bought a house which needed some electrical work done, but it turned out it needed a lot more done than we thought... We haven't moved in yet but basically, the overhead lights barely work and if you plug anything into an outlet then all of the lights turn off. The lights also flicker a lot -- but that comes and goes.

We've been in touch with the 3 closest electricians (the home is in a town under 1k population) and one was nice enough to go to the house for free and look at the outside "meter can." He provided this estimate (copied and pasted exactly), along with a price of $2,102 USD.

The house was built in 1920.

"Included labor/materials (install):

1. 10ft-2inch PVC conduit.
2. 2inch weather head.
3. 20amp Meter panel combo.
4. 4/0 THHN service wire.
5. 1-2pole 60amp breaker (AC unit)
6. 1-2pole 30amp breaker (water heater)
7. Upgrade grounding system."

I thought the grounding system upgrade meant he would turn all of the 2-prong outlets in the house into 3-prong outlets but he told me that doing that would double the price.

(The other two electricians I constacted didn't see the meter in person but quoted "$1750" and "around $500.")

Could anyone explain what upgrading the grounding system would do? Also, does it sound like all of this will fix the problem I've described? I've never dealt with electrical work before and I'm just worried as this is a huge amount of money for people in rural areas like ours, and if it doesn't fix it then I won't be able to afford another try or move in...