Once you find keywords that are viable options for you, click the button to the right of the column to add them to your keyword plan. This will temporarily store your potential keywords.
Once you have keywords in your plan, you can set a daily special lead budget, maximum bid, and placement to receive a detailed forecast of the potential of your chosen keywords.
Once you have a list of ten to twenty keywords for your group, clicking the Review Predictions button will show you:
The number of clicks.
The impressions.
The average position.
The average conversion rate.
This way, you'll be able to see how your potential keywords are performing so you can analyze whether they're affordable for your budget.
Use these results to add and remove keywords until you have a refined list that will help you get the most out of your budget.