405k @ 6.0% yields a P&I pmt of $2,428 a month. The PMI will be at least $180 a month perhaps more. The PMI will probably not be tax deductible, since the borrower's income needed to qualify for this mortgage will be above the threshold.
Taxes will be at least 468 a month. This puts the PITI and PMI monthly nut @ $3,076.18
Add the opportunity cost of interest earned on 45k ($150/month) puts total expense @3,226.18
The tax deduction in the first year would be $24,165. This is the interest paid in the first year. With an traditional, amortizing mortgage, the interest payments DECREASE every month, so your tax deduction will decrease every year. The standard state property tax is tax deductible as well. this would be about $5,616 a year. The total housing expense eligible for deduction would be $29781. Assuming a tax rate of 30%, the tax savings would be $8,934 a year, or, $744.53 a month.
$3,226.18 - $744.53 = $2,481.65 a month net of taxes. If this property would rent for around 2300 to 2500 a month, it seems that this price level is getting close to a rent equivalent. There are additional costs for being a homeowner and the monthly cash flow requirement is still over 3k.