Sorry guy, but I've got to agree with the masses here. It is wrong of you to bandit for all the reasons mentioned, but on top of that, it just makes you cheap.
A bandit situation actually cost me a friendship. I was training in the early 90s to run the California International Marathon with a guy whose PR at the time was 3:17. He wanted to get under 3 hours. I actually hadn't broken 3 hours yet either, so we both were shooting to do so. We had agreed to run our own races before hand. Anyway, we got our hotel rooms in Sacramento, and then the next day we got on the bus to the start line, and when it was time to take off the sweats (it was cold that day), I said, "where's your number?" He said, "I didn't officially enter." I lost a ton of respect for him that day, and we were never quite the same afterwards. He rode the bus to the start line, drank the Gatorade, and did everything except cross the finish line. I got there in 2:55. He got there in 2:59. Later he was so happy about breaking 3 hours, and all I could think was "well, you didn't actually cross the line, so it shouldn't count."