Could somebody give me some advice

[Gage Marshall]

I have a seller with a home worth 300 and a mortgage balance of 255. Her monthly mortgage payments are 1100 with a 3% interest rate. The home can be rented for 2400/mo. I want to buy out her 45k in equity and take over her mortgage subto and wholesale the deal to an investor who wants minumum $300/mo in cash flow. If the real estate investor got a loan for the 45k how much would the monthly payments be on top of the 1100 per month mortgage and what do you guys think I could wholesale this for?