Let me start with this: "semi-professional" doesn't really mean anything. You are or aren't. Next, "semi-professional" triathletes, if they exist, don't race sprint triathlons seriously. If they are serious, and are racing that distance, then they should be laughed off the course. If you are doing a sprint, wear some regular clothes, like a dri-fit t-shirt top and whatever else. I still suggest something with a chamios, as any bike seat feels like a fence post after a while. But guys and chicks that show up like they're ready to bring some serious heat need to be laughed at and brought back down to earth. I laugh now at the tri guys who get all geeked out and go crazy to qualify for boston. I thought it was tough from hearing everyone talk about it so much, then I ran my first marathon in Chicago and qualified by almost 30 minutes. It was the most anti-climactic accomplishment of my life. Now when I hear some guy making a big deal over qualifying for boston at a race, I know I'm going to stomp the sh!t out of them in the race.
I started out doing this sport with a $600 bike and a surfer's swimming experience, no racing. I was a colliegiate runner at the time and didn't have money falling out of my pockets. Yoy don't need a ton of money or cool gear to HAVE FUN. I race at a high level and I wouldn't consider myself top-tier, but I am a good second tier athlete in running and cycling. Obviously every poster here is Ryan Hall, Alan Webb, Meb, Abdi, and maybe even Kenisia Bekele, so you are all making livings off your running. I'm just having fun competing at a high level while I'm still young and don't have kids.
And I'll race you over any distance and be competitive. Don't think all of us tri-guys are pushovers. I win more money on the roads than in Tri's. But I consider myself a triathlete now, more than a runner.
400: 48.8
800: 1:50.17
1500: 3:45.6
5k: 15:01
10k: 31:13
10m: 55:25
1/2 Mar: 1:15:14
Mar: 2:40:01
Oly dis Tri: 1:59:51
1/2 Iron: 4:28:18
Nothing spectacular, but next time you see a guy pass you on a TT bike, don't think he's some schmuck who isn't good at anything. He could kick your ass in a road race but might be looking for the next challenge.