Marathon Versus Triathlon

The time has come for me to set a goal of completing something I once would have thought impossible. Only problem is - I'm not sure which goal I want to set for myself! For the last few weeks I've been toying with the idea of training for a marathon or my first triathlon. Now that I can actually afford to do one I'm trying to decide which I'd like to work on first. A local running store/community has training programs for both that start in July and culminate this Fall. Of course I had to make up a pro/con list for each.

Marathon

This one definitely scares the crap out of me. 26.2 miles .... really? Scary goals can be good though. I cannot fathom how incredible it would feel to finish one and be able to say I'm a marathoner. I also feel like I'm not sure what the next few years in my life may hold for me and I'd love to get one done while I still can.

TriathlonHonestly, if it wasn't for the cost I'd consider training for both. The Tri consists of a 600 yard swim, 18 mile bike and 3.1 mile run. The only real training I'd need to do for the Tri is swimming. The Tri is October 5th and the Marathon is about 6 weeks later and I think I would be okay to do both. 

Option C: Register for the marathon training program and train for the Tri on my own. That would bring the cost of the Tri down to about $300. A student of mine has a Tri bike she's offering to sell to me for dirt cheap (or I may just pick up a bike from Walmart) If I didn't sign up for the Tri training I'd have to find a pool to use somewhere though which would add on extra money, but likely come with a gym membership I've been thinking of getting anyways.

Decisions, decisions!

What would you do?