Their website is theirs, and their webshop is also theirs, to have the same product priced with a difference of 150% in both of these their very own places at the same time, is a heap of baby's after-lunch-got digested-remains, sorry. Their is no excuse for this - this simply is extremely poor management, plain and simple.
Like @James Cook mentions above. A friend of mine made the jump and picked up DTM 13 on steam sale for 8$ cdn. That includes many track and a great starter point. He then picked up a vrp pack and bought a few cars. That is the way to go. Granted the content hits a sale on steam.
IMO, if you are patient, you could wait for a sale for DTM2013 Experience on Steam or Humble as it does drop to fairly low price($6.80) in the past. That pack makes a really good starter pack into the game as it comes with a good amount of tracks. Then, you slowly build up your track list buy getting the European and American track pack.