Trying to decide if i should rehab or sell this property

[Savannah Leigh]

i have a property I just purchased (last week) and am considering either rehabbing (2 unit) or selling out.

Purchase price (total HUD) 12,300 or so
Rehab needed $25,000

would rent for about $1100/month

Offer 1 is $16,000 cash
offer 2 is 12,000 cash and $800/mo for 7.5 months.

How can i objectively decide between A. fix and rent, B. offer 1 and C. offer 2.?

Separately:

if I buy a property at 12k, sell it a week later at 16k, how do I avoid being taxed on the profit? Must I buy another house with the profit, or can I put that into paying down mortgages or other business expenses.