I am not a lawyer, that being said you should seek a lawyer for legal advice. The following is my personal opinion, which may get you in trouble if you don't validate it.
Waivers are social deterrents at best, and if they aren't done properly (easy for people to understand/read with all the important details on the same page as the signature) they don't do much good in court. The reality is that you need insurance to prevent volunteers and organizers [with valuable assets] from being sued [for those valuable assets]. But more importantly, people need to be "properly" trained and use standard practices so that they aren't "negligent." In theory, it would be a waste of time for someone to sue a dirty hippy with $20 to their name. However, if that dirty hippy is considered a dependent of someone that owns a house, car, or some kind of savings... a morally corrupt person could try to sue the parents of that well-intentioned dirty hippy. Regardless of who would rightfully prevail in the end or what the good Samaritan laws are, the person that can float the court fees the longest sometimes wins out. In general you want to avoid this road at all costs.
And that is the cost and benefit of insurance. If you can't afford it yet, you aren't ready to operate as an organization yet. But operating without it puts everyone in risk.
Sincerely,
Jonathan "dirty hippy" Morrison
c: 801-688-0183