Hi. I am a JD PhD, Registered US Patent Agent. I run the IP Coyle Intellectual Property Agency and I handle all patent drafting, filing, and prosecution services. Let me start by outlining what you need for a complete application, since I cannot quite tell what state of preparation your idea & written description are in based on the job post.
1. Is your idea already fleshed out in an "enabling disclosure," or in other words, do you need me to draft the application? Your job post says you only need filing services but this of course is the most important component in the filing process.
2. I assume you want to file a provisional application, rather than the nonprovisional. Do you understand the difference between these options and why strategically it is best to begin with the provisional?
3. You mention also that you may be interested in filing an international (PCT) application. You can actually do both Domestic and International, separately, and that is another reason why starting with a provisional is ideal. It will cost you about $4000 in filing fees to the USPTO to file a PCT, but the provisional gives you one year to come up with the money and reserves the PCT option in the meantime.
Therefore, I am bidding for the cost of filing a US provisional and assuming you have the written description fully ready to file. If not, we need to add more work and fees. I have a website at iancoyle [dot] net where my office details are listed if you want more explanation. Ty