ICO's are garbage because they don't really produce anything, there are no successful stories about ICO's from 1 or 2 years ago that have now turned into working projects. Your proposal won't solve anything, people will be trading tokens over the counter, because it's better than hold a bag of tokens with absolutely zero use. The only way to protect investors from ICO's is by educating them that ICO's are scams.
Some ICO are scams not all, but educating people about ICO is a great way to help them realize how good this market is. If ICO is useless, how come some good coins are come from the ICO and doing well today? Well, we all have our own opinion about cryptomarket so go for it. The price may different from the ICO price but setting a minimum price is quiet not possible for now.
Price doesn't mean anything, during dotcom bubble thousands of companies were worth a lot of money, and then almost all of them were wiped out. This happened because they were vaporware, companies without product, only promises of one, and at some point the market started figuring that those companies will fail to deliver or the product will be poor. Same is happening with altcoins and tokens - they get millions with whitepaper only and noobs see it as success, but in a few years all these tokens will be worth nothing. Checkout what coins were in top 10 in 2013 and where they are now.
Sorry but I don't agree with what you've said.Not all ICOs are scams,we have a lot of examples of succesful ICOs that are used right now and have there place on the market;example:Populous (Profit was over 6000%),Spectrecoin (Profit over 50000%) and even ETH had an ICO back when ti was created.In conclusion to protect investors from ICO's is by education them how to pick an ICO where to invest and not by telling them that all ICO's are scams.
In the real world, no one uses Populos and Spectrecoin. ETH is on the road to more and more centralization, it will lose against Bitcoin in the long run.