I doubt that Inktomi could be less forthcoming with his very "political" answer. I fear that their PFI business model again puts Inktomi in a position of trying to to say two contradictory things at once. On the one hand, they must give people reason to pay to be included in their database. And on the other hand, they much index as must of the web as possible to compete with Google and Fast.
Still, we have observed their behavior and I can answer your question.
1. Inktomi has made a dramatic change in their crawling behavior in the last couple of months. So, what I say here is based on their new pattern. You can find other threads in this forum that talk about a lot of their past behavior.
2. If you pay for a page, they spider it every 48 hours as they say.
3. If you pay for a non-home page on the site, inktomi will automatically include your home page in its crawl every 48 hours. Note this: If you want paid inclusion for your home page and another page on the site, you need only pay for the other page. The home page will be included automatically without paying. You are always throwing away good money to do PFI with Inktomi for a home page.
4. Inktomi runs two sets of spiders. The spiders that serve the paid inclusion program just spider the pages you pay for and do NOT follow links from these pages to crawl other pages.
5. Inktomi has another set of spiders that crawl the entire web, in the normal way, following links it finds to discover new pages. These are the spiders that have been recently re-invigorated after about a year of inactivity because Inktomi finally figured out that their database had become irrelevant and non-competitive as a source of information and had devolved into just a list of essentially paid advertisers.
6. Other threads in this forum discuss places where you can submit for free to get crawled by the inktomi free spider. Inktomi has attempted to close most of those avenues to free submission, but some still exist and it is still an effective way to get indexed for free.
7. Now to the heart of your question: What happens when you have a site with some pages on PFI and other pages that you haven't paid for but would like to see indexed? Your PFI pages will NOT help your non-pages get spidered and indexed. However (contrary to past behavior by Inktomi), if the free spider finds your non-paid pages through its normal crawling activity, those pages will be indexed.