You should engage with many fine Realtors on the board responding to you and negotiate not just the
PMI aspect but also the Sales Price, to cover the PMI costs. Depending on how many Units have sold in the entire complex you may or may not be able to get conventional financing.
Generally, the Builder has at least two lenders on site.
You need to talk to a straight forward lender that can show you your real options in writing. You need to look at a loan scenario with PMI and with the LPMI option so you can decide which is better for you. You may also want to look at an FHA loan since you can get in with only 3.5% down on that program.
Also, here is some information on Dropping Mortgage Insurance:
If you would like more information please do not hesitate to contact me.
Best of Luck,
Erik J. Weisskopf,ABR,CDPE,CRS,GRI
Hope that helps.