You need to start looking for a lawyer immediately. It can make a huge difference in whether you go to jail and, if so, how long. You should always speak to a few different lawyers or get a recommendation from someone. Make sure the lawyer handles criminal cases on a regular basis. You usually cannot hire a lawyer just for the arraignment. You hire the attorney to represent you for the entire case. If you don't have money to pay the entire fee, many lawyers will allow you to go on a monthly payment plan. In most cases, the case will take some time to resolve. At arraignment you will plead "not guilty" and you will be entitled to receive "discovery" which is the evidence they have against you so that your lawyer can evaluate the case. Your lawyer can determine is the evidence is weak or strong and how to proceed. It is always up to the state to prove the charges beyond a reasonable doubt. If the case is weak, you can go to trial or work out a plea agreement. Your lawyer will be able to counsel you on that decision. Don't call Saul.
The cost of a lawyer is based on a number of things including complexity of the case, experience, skill and reputation. The question is not how much will it cost, the questions should be do I want the best attorney and/or who is the best attorney I can hire with the money that I have. This site has some of the best lawyers in Arizona. Search under criminal defense lawyers, call some and see which one you feel most comfortable working with and see if you can hire that lawyer. Many firms, including mine, provide payment plans.
As my colleagues have said, many attorneys allow you to be put on a payment plan. And many attorneys offer free consultations. I would suggest talking to a couple of attorneys. You want to ensure your attorney is knowledgable and has the ability to serve your needs. Most of all you want to be comfortable with your attorney. But get looking soon, you have court in less than a week and things move quickly. With the type of case you mentioned, if you are in maricopa county, may end up in the early disposition court (edc) which means plea bargaining happens quick. Good luck.
It sounds like you have a prior felony conviction(s) (or a "violent" prior conviction) that is making you non-"Proposition 200" eligible (a now statutory provision where most drug possession offenders are required to be sentenced to probation rather than jail).
Most criminal defense attorneys charge a flat fee in cases such as yours. Some charge hourly and require you to pay an amount up front that you can bill off of. In either case, the amount attorneys charge varies with the attorney. Generally, an attorney with more experience will charge more than an attorney that is fresh out of law school.
Like my father always told me, "you get what you pay for," so your best bet is to call around and speak with different ATTORNEYS (not some non-attorney salesperson or paralegal) and find the one that you are most comfortable with and that you can afford.
I am surprised that you already have reviewed a plea agreement without an attorney. Better get one immediately as it seems the process is not slowing down because of any lack of representation.