The arithmetic and the eight rules

The arithmetic

1. Months. Month 1 starts on your sign-up date; each later month starts on the same day of the month (the 31st becomes the last day of a shorter month). A charge is dated on the first day of its month.
2. Hosting. The sign-up term at the sign-up price, then renewal terms at the renewal price, until the years you count are covered. "Whole term paid up front" puts the whole term's price on the term's first day; "billed every month" puts one month's price on every month. A 1-month term is always billed monthly.
3. Domain. Its yearly price on the sign-up date, or 12 months later when it is free for the first year, then every 12 months.
4. Add-ons. Monthly add-ons follow the hosting's billing (on an up-front plan, each term's add-on months are paid with that term); yearly add-ons are charged every 12 months from sign-up; one-time add-ons on the sign-up date. A first price applies to the months before it ends.
5. Setup fee on the sign-up date. Sales tax is added to every charge and each charge is rounded to the cent.
6. Real price per month = every charge in the years counted, divided by the number of months.
7. Leaving early after N months = every charge dated before month N+1, minus a refund: inside the money-back window (days from sign-up to leaving, counted on the calendar) the hosting charge of the term in use comes back, but never the setup fee, domain or add-ons; after it, with "unused whole months refunded" and an up-front term, the unused months of that term come back. Hosts' own refund rules vary: read theirs.
8. Side by side compares money paid so far, month by month, and names the months when the cheaper offer changes.

The eight rules

R1 Renewal jump

Renewal price at least 1.5 times the sign-up price: Worth a question; at least 2 times: Look hard.

R2 Sign-up price ends inside the years counted

The sign-up term is shorter than the years you count and the renewal price is different. Higher renewal: Worth a question; lower: Good to know.

R3 A lot of money up front

Day one costs $100 or more, or a term of 36 months or more is paid up front with no refund after the money-back window: Worth a question.

R4 Free domain starts billing

The domain is free at first and has a yearly price that starts inside the years counted: Good to know.

R5 Add-on first price ends

A monthly or yearly add-on's lower first price ends inside the years counted: Worth a question.

R6 Short money-back window

A term of 12 months or more paid up front with fewer than 30 money-back days: Worth a question.

R7 Setup fee

Any setup fee: Good to know.

R8 Advertised price far below the real one

The advertised monthly price is less than two thirds of the real price per month: Look hard.

The rules point at things to ask about; they do not say an offer is good or bad. Hillbilly Hosting sells no hosting and recommends no host.