At $100/month you could go in with a couple friends/associates/partners and get a dedicated server. You'll get the same benefits as your semi-dedicated server with the added bonus of knowing the people you're sharing the server with and having a little more control over the configuration of the machine.
Speaking for myself, I wouldn't take advantage of it currently, as I'm not running any sites that warrant it. If I was running anything more important, I'd first look into sharing a dedicated machine with someone I know, or co-locating my own, depending on cost and my specific needs.
I think the most I would pay for hosting personal sites is around $50/month (I'm currently paying $20). For commercial sites I would be willing to pay more, as there's more at stake and I would (hopefully!) be making money from them as well.
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