Siacoin's current valuation stems from the number of tokens x price = network value (crypto version of market cap). This is a far cry from the valuation model used for companies like Dropbox. Apples and oranges. For now, devs are largely setting the valuation since they decide how many tokens to create for a particular project.
The 50 cent future price is speculation from hedge fund guys I met in NYC the week of Consensus and Token Summit. The reason they're so bullish is because of the fact that Sia is a protocol-layer project with a major use case that consists of many potentially disruptive applications.
In the Web 2.0 era, the lion's share of value was created on the application layer of the TCP/IP protocol. This is why the founders of companies like Google, originally a search company, are billionaires while the creator of the world wide web protocol Google search was built upon - Tim Burners-Lee - is not even rich.
In blockchain, most of the value will come from innovation on the protocol layer. This is why blockchain hedge fund Polychain Capital only backs projects that are innovating on that layer. This is why they're getting behind something like 0x Project (decentralized exchange on the protocol layer -
not front end like Poloniex or Bittrex) and not something like Status (mobile browser and messaging platform built on top of Ethereum protocol). Developers who build the infrastructure will reap the fruits of their labor.
Pro tip: Research any project that is supported by Polychain Capital and Union Square Ventures. Get on those ICOs. Look up Fred Wilson and find his blog. Read the post he wrote about ICOs.
Listen to this podcast for more insight:
http://a16z.com/2017/04/03/cryptocurrencies-protocols-appcoins/Sia has a big future ahead of it. A lot of the concerns being spouted are utterly petty and miss the big picture. Don't think like the small man. Educate yourself while it's still early. Information is everywhere, but the desire to truly learn is scarce.
Go to events in this space. Whatever money you spend on getting to and from the event location and for event tickets will come back to you 20x or more in the form of the network you build. At the very least, find meetups in your area or create one yourself. It's still early guys, so if you're truly passionate about this new technology, go all in.