I've had a "Provisional Patent" a few years back. That is less expensive and gives you a year from that point to promote it at trade shows, personally to companies etc with out them being able to steal it. Nobody bit on mine, but after the year had passed a company did in fact make it as "public domain".Now they did actually improve it a little bit, but I still consider it stolen. A patent attorney is really expensive 5-10K+ depending on how complex. Look up on how to patent it yourself. My brother has 3 patents he did himself but he is also an architect so he knows how to draw it up with the right specs. Good luck man, I still have a few I am working on, need funding.