Does it make sense to self publish on Kindle Store?

 Amazon has recently been making waves by signing up 150 authors in the last quarter, to write books on its platform. Naturally, the mainstream publishers are unhappy about Amazon's ambition to transition from retailer to publisher, but for the author, this represents wider choice. Now, even before Amazon entered, it offered authors a 70% royalty, with some caveats like $0.15/MB charge for electronic delivery, 30% IRS withholding tax, and 70% only on few areas(else 35% w/o the delivery fee)! So I can my own analysis of the 70% scheme, assuming sales are in the eligible countries at different list prices, and found that to get that $100 royalty check(threshold to issue check is $100), one needs to sell 74 books priced at $2.99. Considering that a print run of 10,000 copies is considered good for a book on which an author may get say Rs 20(max)=>$0.4/copy, those figures are quite good. Lets see if I use that platform someday as a test drive of my writing talent

Analysis of Amazon 70% royalty scheme
List price($)	0.99	1.49	1.99	2.49	2.99
Royalty @ 70%	0.69	1.04	1.39	1.74	2.09
Data Cost @ $0.15/MB	-0.15	-0.15	-0.15	-0.15	-0.15
Net From Amazon	0.54	0.89	1.24	1.59	1.94
Net After 30% witholding tax	0.38	0.63	0.87	1.12	1.36
Sell these many for $100 check	264	160	115	90	74
Net Realization to author(% of list price)	38%	42%	44%	45%	45%