You can maybe get $100-$200 if you find the right person. Since these are "brandable" domains you need to find someone that has an idea or vision for them. If the domains were based on a keyword(s) there's a formula to figure out the value.
Obviously RebelHost could be used for a hosting company but I'm not sure I see what's special about that versus any other word + host.
You can try estibot or valuate.com but I don't think they will give a very good number since you are trying to sell on the brand.
Valuation of a domain can either be done by revenue generated by your your business and lot of other things. There are many domain having 1 pagerank but they give a lot business. once they reach its marginal equilibrium of business level seller take it for valuation to sell it.
It depends. I think in order for you to get top dollar for one of domains which is what you want you'll have to wait till the right buyer comes. Either wait for the right buyer or find someone who owns a domain that is like those contact them and see if they offer you a decent plan.