How to manage the project without project manager?

There are few points forced to manage the project without Project Manager:
- Project is small in terms of quantity of work and number of people to carry out that work
- The complexity and risk is low
- The sponsor feels that they do more on technical jobs or R&D or performing case study, so that the need of the project management is minimal (this point is opposite to the above points as the technical jobs, R&D and case study have more uncertainties and challenges)
- No budget to cover the cost of Project Management indeed Project Manager

Estimate the agile project's budget using story points

The budget of the project calculated mostly based on the effort. In agile projects the budget can be calculated based on story point also. The project manger needs to have clear input on the velocity of the team to calculate the budget.

Project Budget = Cost per Story Point * Total Story Points

Cost per story point = Cost of resources based on the effort spent / Story points per week

Assume you have team size of 8 with the rate of 80$ per hour.
The total working hours spent by person per week is 40 hours.
Total cost per week = 8 (team size) * 80 (rate in $) * 40 (hours/week) = 25,600$
Assume based on the velocity, you team able to complete 16 user stories.
Cost per story point = 25,600 (Cost of resources based on the effort spent) / 16 (Story points per week)
                                      =  1,600 $
Assume you have 500 story points planned for the project.

Project Budget = 1,600 * 500 = 8,00,000 $

What’s New in PMBOK Guide, 5th Edition

Are you ready for the newest guide to the Project Management Body of Knowledge? PMI is poised to release the new version of the PMBOK Guide before the end of 2012.

I have highlighted what’s new in PMBOK5 compare with PMBOK4 below:
Total numbers of process in PMBOK4 are 42.
Total numbers of process in PMBOK5 are 47, the Project Stakeholder Management knowledge area has been added newly.