To figure out how much you should pay for your service provider, you have to figure out what it is you are trying to accomplish with your list and who you are trying to reach. If you are a business owner and serious about your newsletter, you will probably want to pay for your services, because you will usually get more reliable service and more options to choose form. If you are just setting up a list for entertainment, then a free list provider will probably offer just about everything you will need. Make sure you know what you are looking for and what you want out of your list when shopping around for a service provider. Here are some tips on what to look for when weighing costs.
Most service providers offer deals.
Look into them. Some will give discounts or specials if your list is over a certain size and you move your list to their service. Or 1 month free if you sign up right now. Deals are deals. If you can save money without sacrificing quality, do so.