there are many factors in your question. A ninja of this time frame will be anywhere from 2000 to 3500. Monthly cost depends on how long you plan to pay for it. But financing is usually done through a dealership and it is highly unlikely you will find a used Ninja right now. You might not even find a brand NEW 250 Ninja right now, they are selling so fast. All of the dealers in my state are sold out and have waiting lists. Almost all brands of 250-500cc are sold out. If you do, they offer low low payments ( $79), which may be interest only, read it carefully. You should expect $100-$200/month. Your best bet on finding one will be another rider, and they arent gonna want to take payments. There are a few dealers that specialize in only used bikes. You may see something else you like. Your down payment, your credit rating, and length of financing determines monthly amount. Call or visit several insurance agencies in your area, they will give you a quote even if you dont have the bike yet. Rates vary by state and city. I know State Farm rates are based on the size of the bike, not all of them do that. Males under 25 are the most expensive group. Clean drivers can pay as low as $25 ( over 25), and Ive seen bad records pay as much as 2500 for 6 months. If you still live at home, you can see about making it a multi-car policy with a parent, assigning you are the only driver. Take the Motorcycle safety Foundation class and it should make your insurance go down more too. stop by and visit Kawasakimotorcycle.org forum. Ride safe!