How much is a life worth?

Educate me about life insurance. I'm female; under 40; non-smoking; the primary wage earner in our family (I earn 2/3 of our income, my partner earns 1/3); we own a house and have a son who will be one year old in July. For many years, I had $100,000 in life insurance through my employer, however this benefit is no longer available to me so I've started shopping for insurance and, I have to say, everything seems prohibitively (ie: $100+ per month) expensive, and I'm having a lot of trouble sorting out the options. We're guessing that I need about a $250,000 policy (which would pay off our house and car, my funeral, plus leave some savings for our son). What are the real-world differences between Term Life, Whole Life, Variable Life, and Universal Life? Which is the "normal" thing for someone in my situation to buy, given that our budget is very tight? I know we can't afford to be without insurance if something happens to me, but honestly an extra $100 per month would put a huge strain on our budget right now, so is this a "reasonable" price for a young-mom-non-smoker to expect, or are the internet quotes I'm seeing too high? I realize I should speak with an agent about this, but a) I'm working two jobs and its difficult to take time away from work to make an appointment and b) frankly, I feel as though if I go into a conversation with an agent uneducated I'll end up getting sold something more than I need or want. So please, educate me about life insurance.