Help me decide whether to take this used roadbike?

[millefolia]

Thanks! The thing is, though, on my hybrid I can push hard enough that my legs feel tired before I feel out of breath at all. That's why it does seem to be something related to this bike and I don't understand what--would a road bike be working my lungs harder than my hybrid does? Maybe I should ride them both today one after the other and compare again, rather than just riding the new one while I'm deciding.

As far as price and components, it's $300 and the components appear to be Raleigh brand, as that's the only label I could find on them (the rear derailleur even says "Raleigh" right on it). That makes me suspect the bike may be overpriced component-wise, but if the bike works well for me I'm not sure how much that should matter. Thoughts would be welcome on that as well.

Edit: OK, there's something in each of your replies that I missed! Sorry, just woke up. :-) Replying to those now:

Catriona: I see your last line now, suggesting that the road bike is letting me work myself harder. That could well be, and that would answer my first paragraph in this reply!

uforgot: I'll Google exercise induced asthma later today. I don't think that's the case for me as I was able to go running last year without breathing harder than I expected, but that will tell me whether it's something that could have started since then. I can post pics later, but now I'm running to get to work!