What you'll pay
Most lawyers charge according to the number of hours worked on your case. Hourly rates can vary tremendously, as low as $75/ hour to as high as $250/ hour, depending on the geography, sophistication of the project, and the amount of expertise needed.
If costs are your primary concern, make it clear to the attorney from the getgo so it can be addressed appropriately.
Ask any lawyer you're considering whether they round off the time worked, which could have a big impact over time.
Note that hiring a specialized lawyer does not necessarily mean an automatic increase in costs, since it may take a more experienced attorney less time to reach the same result.
For standard needs, such as drafting a simple contract, specialization isn't necessary, and any lawyer with general corporate experience should be up to the task.
For this and other standard needs, ask for a cost estimate. If you are a small but growing company, you may be able to negotiate a reduced fee, with an understanding that once you reach a certain size, you will pay a full rate.
Regardless, ask for an up-front budget and a contractual agreement regarding costs and payment.
While rates can vary depending on the geographic market, price will more often be contingent upon the quality and/or size of the law firm and the seniority of the attorney handling your case.