I am trying to reconstruct the image below in tikz, and I think I have done a fairly decent job.
The problem is that my code is a mess. Is there any simple clean way to produce this image?

My main problem was the axis, and somewhat the scaling. Also the nodes are a huge mess ^^
\documentclass{article}
\usepackage{tikz}
\usepackage{tkz-euclide}
\begin{document}
\begin{tikzpicture}[x=0.02cm,y=0.02cm,scale=1]
\tkzInit[ymin=-40,ymax=390,xmin=-40,xmax=540]
\tkzClip
\draw[help lines,ultra thin,dashed,gray!50!white] (-50,-50) grid (550,400);
\coordinate [label=below right:{50}] (x_1) at (50,0);
\coordinate [label=below right:{}] (B) at (0,390);
\coordinate [label=above right:{\Large $y$}] (U) at (0,350);
\coordinate [label=above left:{\Large $x$}] (A) at (540,0);
\coordinate [label=below right:{50}] (x_1) at (50,0);
\coordinate [label=below right:{100}] (x_2) at (100,0);
\coordinate [label=below right:{150}] (x_3) at (150,0);
\coordinate [label=below right:{200}] (x_4) at (200,0);
\coordinate [label=below right:{250}] (x_5) at (250,0);
\coordinate [label=below right:{300}] (x_6) at (300,0);
\coordinate [label=below right:{350}] (x_7) at (350,0);
\coordinate [label=below right:{400}] (x_8) at (400,0);
\coordinate [label=below right:{450}] (x_9) at (450,0);
\coordinate [label=below right:{500}] (x_10) at (500,0);
\coordinate [label=below right:{0}] (O) at (0,0);
\coordinate [label=above left:{50}] (y_1) at (0,50);
\coordinate [label=above left:{100}] (y_2) at (0,100);
\coordinate [label=above left:{150}] (y_3) at (0,150);
\coordinate [label=above left:{200}] (y_4) at (0,200);\\
\coordinate [label=above left:{250}] (y_5) at (0,250);
\coordinate [label=above left:{300}] (y_6) at (0,300);
\coordinate [label=above left:{350}] (y_7) at (0,350);
\coordinate [label=above left:{\bf Kostnader per m\aa ned (kroner)}] (R) at (310,350);
\coordinate [label=above left:{\bf Ringetid (minutter)}] (K) at (540,20);
\tkzDefPoint(0,-50){C}
\tkzDefPoint(-50,0){D}
\tkzDefPoint(0,87.50){S}
\tkzDefPoint(500,337.50){T}
\tkzDrawSegment[thick,-stealth](D,A)
\tkzDrawSegment[thick,-stealth](C,B)
\tkzDrawSegment[ultra thick,red](S,T)
\end{tikzpicture}
\end{document}

My main question is, if there is a simpler way to create the axis. (nodes?)


pgfplotsis the recommended tool but I have also fun to write codes with my packages. The code of the OP is not very optimized.tkz-euclideis used to create geometrical drawings.tkz-baseis a tool for drawing with a cartesian coordinate system. You can define your axes with\tkzAxeXandtkzAxeYwith the optionsxstepandystep(see my answer). – Alain Matthes Nov 21 '11 at 16:40