vbulletin does not install into photopost correct
photopost integrates into the vb
As noted you really need to use the contact us link to get pricing. The steps are this though
would have to be installed
2. the vb
impex system which is a separate program would need to be installed and ran to import your photopost users into vb
3. photopost would have to be reinstalled to integrate with vbulletin
4. There is a script here also that needs to be ran to realign userid's when you switch forum integrations.