I don't think what you are looking for is called "normal price". we don't actually have anything with that name. you can call a manipulated price (whether a bubble which is a higher price, or a big dump which is a lower price) as abnormal price. for example somewhere around $14k was normal but the rise to $20k was not and then the drop to $5900 was extremely abnormal!
additionally looking for prices like this is only good if you want to either make a one time long term investment like buying 21BTC in one go and then hold it for years, or it is good for day trading. but if you are investing in bitcoin constantly like buying some small amounts (20-50 bucks) every month from your salary then it shouldn't really matter what the price is at!