You should be able to do it on your own, if you are handy with your tools. Main thing is to fasten the dish firmly to the wall or parapet. Some masonary work is usually required. 1000 bucks is too much for such a small job. I am sure soon other people, maybe DishTV guys, will do it for Rs 200 or less. DishTV people charge 200 right now. You might ask some DISHTV lads at a shop or so.
But remember, your address details at
Tata Sky will remain unchanged. So if you are in Bombay, you will continue to NOT get HBO and Star Movies even after you moved out. So this option is splly good if one is moving to Mumbai but not if one is moving out of Mumbai.
Also may face problems if a problem arises and you need service. So you may have to hurriedly inform of change of address then, and ending up paying 1000 buck you thought you saved. But a lot of people take STB outside India too, without informing TataSky (obviously).
I think its well worth the risk to get it installed by others for Rs 200 or so. Most people abroad do such stuff on their own.
There are lots of resources on the net, try googling with keywords like 'dish installation'.
Try sites of Analoguesat , www. satallites.co.uk whose written two books on How to install satallite dishes.