If you only host your own sites and they aren't important to have running all the time, sure, just make sure you have really good off-hosting backups running.
If the sites hosted are important, and you can't risk losing access to them or them going offline for an extended period, then no, you can not use a shared license, because some day litespeed might discover that license is used by the reseller in that special way that violates their terms and not just the license may get revoked, but your server IP may get blacklisted in their system as well... Not worth the gamble.
I found some nice deals buying legit licenses at cpanel.net. That's just about the best deal you can get, unless your host has a special.
