Price range is up to you. Most "general purpose" detectors you will find are in the $200 to $1,400 price range. If you start too low you will likely outgrow the features soon. Start too high and you might be frustrated with how sensitive the unit is to set-up and changes. You can get good, servicable detectors for well under $400 that will do the basics well. As a rule of thumb, the higher the price the more successful you will be in the marginal conditions.
A LOT depends on where you intend on huntng. Beaches, parks, trashy areas, woods, foundations, fields, plowed fields, etc.
Be sure to leave aside enough kitty for a good set of headphones and a good digging tool. A pinpointer will also make you a better hunter by speeding up the dig and recover time.
Come back with your comfort $ level and your list of intended main search areas and we can narrow the field for you.