Frantic,
I heard about the DUMMY tickets you are talking. Actually my parents came here 4 or 5 times in last 5 years. They have multiple entry 10 year visa. I have extended their stay twice. Our location is Boston. Extension is not a problem, if you have a good reason (or moreover if you write a valid good reason in a very kind and polite manner for the reason of extension). This time I could not believe that they got their extension in 10 days after we mailed their application. We mailed their application on April 19, BCIS received it on April 23 and they got approved on May 1 (checked online) and we received their approval after 5-6 days in the mail.
Regarding Dummy ticket, you have to purchase one way ticket from India to US(restriced to get a very good price) and one way ticket of the same airlines (full price, which is very expensive but you can return it with approx. $50 to $100 penalty depending on the airlines). My friend has done that but personally I have not preferred to do that. What I did is, my Parents purchased a full restricted ticket for 4 months and came here (we were sure that we will apply for their extension as we were expecting a baby). So they came here on a 4 month ticket and we got the extension and we have thrown their returning ticket and purchased 6 month round trip ticket (from USA to India) for them and they came here after 6 months again to USA. Now I read that some people have written that at the POE, the officer has asked for the return ticket. In our case, it never happened (always in Boston) but I am not sure if this is always the case in Boston. I am not sure but buying one year ticket from India, persoannly I will not prefer as one year is a long time and what if in the worst situation
(I am not at all hoping for this in your case) they refuse the extension. Few months back one of my friend (also in Boston)got RFE in his parents I-539 Extension Application. Also One year ticket is not exactly double in the price but it is almost double.
Decide keeping everthing in mind and Please let me know if you have any other questions.
Hope this helps.
Very Good Luck for your parents visit and NEW addition to your family.