Can I get married again in a different state and sign it with my new married last name and avoid having to pay the $700?

Check with the local court. Basically a name change shouldn't cost that much just a filing fee and you should be able to handle the paper work yourself. I'm not sure if you want to change the name on your nursing credential or on your driver's license. Talk to a lawyer in your county about this. The general rule is that you can use any name you want so long as it is not for the purpose of defrauding creditors. DMV and Social Security generally require some kind of document to allow a name change getting married in another state might solve your problem the cheapest way possible. But, check it out locally before going to that extreme step.