Do witness and executant sign on PoA on last page?
Yes, all have to sign on last page.
Does PoA holder in India need to sign before attestation by Embassy?
That person can sign when he/she receives this PoA in India.
Price of attestation is per page or per PoA?
The price is per page of attestation.
If you want sign and stamp only on last page, then pay only for 1 page. Else, pay for all pages.
I recommend to get sign and stamp on all pages.
Also, if the #atlanta-ind-embassy (Atlanta embassy) will charge only for 1, they will return the rest of the money orders. Each embassy has their rule to charge.
So, I would advice to create 4 different money orders so that if they only charge for one, the rest can be returned to you.
Where to get return Shipping Label and Envelope?
Prepaid return label can bought from any courier service like USPS, UPS or Fedex. They all sell it. You can even go to their website, buy and print the label.
They all give the free envelopes too that you can pick up from any of their stores.
Where to get money order or Cashier Check?
Walmart sells money orders in their stores. Almost all grocery chains sell money orders too.
Cashier check can be made from your bank account. Visit the branch and get it. They will charge approx. $5 per cashier check.
Money order in Walmart is cheapest. They will take less than a dollar as fees.