Does our technology infringe another patent?

You need professional help. At that point the cost will depend on the situation and the approach you want to take. If you're familiar enough with your field of technology that you can identify your main competitors, it might be sufficient to perform a targeted freedom to operate search, i.e. one that just identifies and analyzes patents owned by a few competitors rather than a "scorch the earth" search that looks throughout the entire technology area. In my opinion, this is going to be the most efficient approach that doesn't leave you with unreasonable risks. The cost could be as little as a few thousand dollars if there aren't many patents and no problems are found. It could be much more if you need to try to invalidate one or more patents or get a written opinion to reduce your exposure.