My first road bike was an $800 aluminum Trek 1000. It had Tiagra and Sora and I put about 5K miles on it without anything breaking. This might sound strange, but I didn't realize what a great bike it was until I upgraded to my $2500 carbon fiber Madone which is all Ultegra. I absolutely love my Madone, but the 1000 was an excellent bike too. And there are certain things I miss about the 1000, like better stability at really high speeds.

Starting with an entry level bike was the right choice for me because I was brand new to cycling and I wasn't even sure I would like it. And I knew I could upgrade, which I did after 18 months (and I sold my 1000 for $400). But it's an individual thing. So I say spend what you can afford and have fun shopping for your bike