Why the host's legal status actually matters
A hosting company has to pay its shareholders. The simplest way to do that across a fleet of small accounts is well known: a cheap first year, then renewal at the real price. The mechanism is not illegal, it is simply incompatible with a budget voted a year in advance.
By-Hoster has no shareholders. The price shown at sign-up is the price on the next invoice, and on the one after that. It is less a marketing promise than a consequence of the structure: there is nobody to hand the difference to.
The same applies to support. Questions reach the technical team directly, with no call centre and no filtering tier. For a volunteer meeting an error message on a Sunday evening, the difference is tangible.