If your still looking to buy, I'm flying into Goa before Christmas and have lots of contacts who could find you a Good bike. A 350 will probably be fine for you but if you fancy a 500, go for it. They're really not a problem and with a couple of contacts you will be able to find spare parts.
I have a 2009 350cc Classic, often ride it with luggage & passenger - it's a pleasure to ride although at times a little sluggish. I also have a 2009 500cc Machismo, I love it!!!
A brand new 350cc TwinSpark is 104,000 inr on the road, including number plate. Second hand the prices are as many as second hand bikes, choose well. And make sure the original paperwork comes with it.
I have not exported myself but have a good friend in Rajasthan who prepares bikes for export. Check the rules in your own country but my understanding is that you may avoid high import duty if your bike is old enough to be regarded as a classic.
Daily living costs: India has a high inflation rate and costs are rising fast - it is also a country where abject poverty exists side by side with luxury and extravagence. What you spend is up to you.... survive, treat yourself, find a balance and it won't break the bank.
If you need any help, contact me from my website. www.samlovett.co.uk
Sam Lovett Motorcycle Tours
Creating great motorcycle journeys & adventure on two wheels