price range its best to have:
buying: below 90 and under; but even at 90 its still a gamble. the lower buying cost the better for you.
selling: above 150+. the sell prices change everyday.
the chances of getting a decent sell price is a bit difficult...I believe the game was built to ask your friends if they have good prices and go to their island.
you can also:
if you've waited the week and there hasn't been a decent price on your island, you can sell your turnips for whatever price they're asking at nooks OR you can visit a friend to sell them. ive sold mine at 95 when I had too lol!
you can leave spoiled turnips on the ground in order to attract ants
if you stick with turnip stalk marketing daisy may will give you recipes that are seriously great as well.
