To try a tri or not to try ...

I really want to do a triathlon. Why? Because triathletes look cool.
I think, or well, I should be able to become a pretty competitive triathlete with some training and races under my belt. I am a relatively strong runner and my swim is above average than most triathletes. The cycling section would be the main problem, however I am sure I can handle it.
Unfortunately > no time to practice 3 sports > but still I want to do a triathlon.
There is one going in in exactly 7 weeks and I have 3 more weeks before the registration closes.
How things look so far: Pretty much no swimming in the last 10 months. Definitely no cycling in the last 306 months. Lots of running though if that counts for anything.
7 weeks though ... if I can get 2 swims per week I am sure I can go under 30 minutes in the 1500 meter open water swim easily.
7 weeks .... with a bit of commute cycling I can probably manage to get under 80 minutes for the 40 km leg.
Transitions would be the enemy to beat. Not used to this multi-sport deal and my legs might not be able to take the changes.
To try a tri or not to try.