Unless you have a host that purposely goes down on a schedule, that’s impossible to answer. All hosts have problems, though.
No host should go down every single month, so it’s hard to put an average on anything.
I think I’d avoid a host that advertised an amount of downtime to expect. It would sound like they’re not trying hard enough to avoid it.
Anywhere up to $97, if you use a promo code that many of us have in our sigs. DH gives you $97 referral fees, which you can turn around and pass onto new customers. You can do the same when you join–or you can just refer people and keep the fee.
It’s all done through shell access, which is available on all plans.
Save up to $96 at Dreamhost with 96DOLLARSOFF promo code (I get $1).
Or save $97 with TAKESEILERSCASH.