Familiar Upgrades

I see that there is an option to upgrade familiars to Combat, Power, or Spell Familiars. The question I have is; when is this done?
Do you have the option of upgrading a familiar at some point after you acquire a familiar?
Or do you have to announce the kind of familiar, if any, before you roll? Which, if you did, would suggest that you would have to pay the upgrade cost before you roll and then find out if you get the familiar.

To me it seems overly harsh to tack on the upgrade cost to the rolls since you pay that even if you lose the rarity roll.

I told you know one uses that Rulebook. All anyone knows about familiars is shadow warriors warband in the 2002 annual. You should upgrade to the Bordertown Burning Supplement. That's all I'm saying.....

The BTB "supplement" is light on rules and while it mentions having familiars it does not tell you the first thing about them, so ......

The rules for Familiars are where? It might help your question get answered if you provide background. Your question is about something obscure thus many of us may not have even used the rule. (Or like myself are not aware it existed.)

I only know of familiars presented in the warband listing for Shadow Elves which are available for all spell casters and the familiars presented in the warband listing for the Sorcerous Society from Letters of the Damned 4. I do not recall either of these rules mentioning the ability to upgrade familiars though.

Oh and welcome to the forum! I see that you've already posted in quite a few threads.

Ah I see the issue now, the crazy rule book I printed out has an extra part about upgrading familiars that is not in the original shadow warriors list. Right once again I am getting burned by non-canon fan created yahooery. This blows.

Indeed.