I respect and agree with Steel Charlie on this. Not just because he's right about the barcons (if you're going to reposition all the way to the end of the drops to shift, you might as reach to the downtube), but also because he didn't use the *word* "brifter".
Barcons get touted for simplicity and reliability, but I've toured thousands of miles with STIs and never had a single problem. Like Charlie, many of my high milage STI bikes are still going strong.
To the OP, there are used latest gen Shimano groups of Claris and Sora on ebay right for less than 200 bucks.