I will prefer to buy later on the exchange when I observe the project market demand, the type of exchange listed, any developmental plans by the team. Etc. I won't risk investing in ICO and then deal with exit scam projects.
If the project is good then the price in the exchange will be expensive, I prefer to invest in the ICO rather than the exchange, but choosing a good ICO is important because of the many scam projects, and one ICO that we deserve is AMMUT.
You are right, but you need to find a very good potential project in the market, in the current situation of the ICO's it is a very tough job to find the best ICO because daily we are seeing many fake companies. So we need to keep track the ICO's and start investing in it only when they start listing in the exchanges only.