1:1 Computing costs are a difficult thing to nail down, because there are so many factors that go into it. I worked with GeSCI's Roxanna Bassi to create a worksheet to help guide cost calculations. I took a first stab four years ago, and came out with a $972/laptop cost over a 5 year program. To say that that cost estimate was not popular at the time would be an understatement.
OLE Nepal has put together a great TCO of the laptop program, based on their pilot project. Where I pieced together training budgets from USAID ICT4Edu projects and Internet connectivity estimates from UN/ITU global averages, they have on-the-ground numbers, (and a few ideal estimates on repair costs). The total for a 5 year program in Nepal? We're still looking at $753, if you read carefully:
Per unit cost to implement the project comes to be Rs. 27,628 (US $ 368)1 during the project/pilot phase considering 26 schools in six districts and around 2100 students and teachers. At present, if the XO laptops are assumed to have life span of five years, and everything else associated with the pilot/project is assumed to remain constant, then per child cost per year for next 5 years (for a child who uses the XO from grade 2 to grade 6) can be calculated as Rs. 5,500 (US $ 77). Per unit cost or per child cost can come down significantly if the number of students are increased as some of the costs associated with the project such as content development remain constant no matter how many students are targeted.
So $368 in setup, plus $77 per child per year, for five years (368 + 77 * 5) comes out to USD $753. They use a surprisingly low (2.5% of machine costs) combined hardware failure/replacement/support cost. It spreads Internet and network fees across a few different cost silos, but overall those fees appeared low compared to the estimates I used in the 2006 TCO. This is likely due to costs decreasing over time, and local variances in connectivity costs.
All in all, worth a read as to the areas which ended up being core in the program (including, thankfully, teacher training!), and deployment costs.