Finally I get access to airdrop but now there is no exchange where you can buy 100 coins...

This should be priority for devs, or to postpone air drop until we get working exchange.
You can get DeepOnions from Nova Exchange. Till the end of November you can use the exchange as you have always used. Only beyond that some of the functionalities start getting crippled. Incase you dont want to trade there, you can ask for a trade on DO forum. I am sure somebody would sell you a few Deep Onions.