tkinter Application object has no attribute for

i'm kinda new tkinter and i ran into a problem while using tkinter with python. I'm trying to get all of the buttons i have right now to take a number and add to it if the button is clicked or not, i ran into a wall and i have no idea how to fix it. Here's my code for reference.

from tkinter import *

class Application(Frame):
def __init__(self, master):
    super(Application, self).__init__(master)  
    self.grid()
    self.create_widgets()

def create_widgets(self):

    Label(self,
          text = "Enter information for services you need on your car"
          ).grid(row = 0, column = 0, columnspan = 2, sticky = W)

    #Oil Change
    Label(self,
          text = "Oil Change"
          ).grid(row = 2, column = 0, sticky = W)

    self.is_itchy = BooleanVar()
    Checkbutton(self,
                text = "$26.00",
                #error here
                variable = self.oil
                ).grid(row = 2, column = 1, sticky = W)


    #Lube Job
    Label(self,
        text = "Lube Job"
        ).grid(row = 3, column = 0, sticky = W)

    self.is_itchy = BooleanVar()
    Checkbutton(self,
                text = "$18.00",
                variable = self.is_itchy
                ).grid(row = 3, column = 1, sticky = W)

    #Radiator Flush
    Label(self,
          text = "Radiator Flush"
          ).grid(row = 4, column = 0, sticky = W)

    self.is_itchy = BooleanVar()
    Checkbutton(self,
                text = "$30.00",
                variable = self.is_itchy
                ).grid(row = 4, column = 1, sticky = W)

    #Transmission Flush
    Label(self,
          text = "Oil Change"
          ).grid(row = 5, column = 0, sticky = W)

    self.is_itchy = BooleanVar()
    Checkbutton(self,
                text = "$80.00",
                variable = self.is_itchy
                ).grid(row = 5, column = 1, sticky = W)

    #Inspection
    Label(self,
          text = "Inspection"
          ).grid(row = 6, column = 0, sticky = W)

    self.is_itchy = BooleanVar()
    Checkbutton(self,
                text = "$15.00",
                variable = self.is_itchy
                ).grid(row = 6, column = 1, sticky = W)

    #Muffler Replacement
    Label(self,
          text = "Muffler Replacement"
          ).grid(row = 7, column = 0, sticky = W)

    self.is_itchy = BooleanVar()
    Checkbutton(self,
                text = "$100.00",
                variable = self.is_itchy
                ).grid(row = 7, column = 1, sticky = W)

    #Tire Rotation
    Label(self,
          text = "Tire Rotation"
          ).grid(row = 8, column = 0, sticky = W)

    self.is_itchy = BooleanVar()
    Checkbutton(self,
                text = "$20.00",
                variable = self.is_itchy
                ).grid(row = 8, column = 1, sticky = W)

    #Buttons
    Button(self,
           text = "Click for total price",
           command = self.tell_story
           ).grid(row = 9, column = 0, sticky = W)

    self.story_txt = Text(self, width = 35, height = 5, wrap = WORD)
    self.story_txt.grid(row = 10, column = 0, columnspan = 3)

    Button(self,
           text = "Quit",
           command = quit
           ).grid(row = 9, column = 1, sticky = W)


def tell_story(self):
    """ Fill text box with new story based on user input. """
    # get values from the GUI
    if self.oil.get():
        print("Goofus")

    # create the story
    story = Price

    # display the story                                
    self.story_txt.delete(0.0, END)
    self.story_txt.insert(0.0, story)




root = Tk()
root.title("Joe's repair shop")
app = Application(root)
root.mainloop()

Here is the error i am getting

Traceback (most recent call last):
File "C:\Users\Kevin Holstein\Desktop\Classes\Python\Labs\Lab 10\Repair shop 
kholstein.py", line 127, in <module>
app = Application(root)
File "C:\Users\Kevin Holstein\Desktop\Classes\Python\Labs\Lab 10\Repair shop 
kholstein.py", line 8, in __init__
self.create_widgets()
File "C:\Users\Kevin Holstein\Desktop\Classes\Python\Labs\Lab 10\Repair shop 
kholstein.py", line 24, in create_widgets
variable = self.oil
AttributeError: 'Application' object has no attribute 'oil'