Actually, we might take this as an opportunity to start weeding out some of the fauxtographers that are flooding the streets. How about a reply along the lines of, "Yes I do. I have $XXXXXXXX invested in my gear and anyone else wanting to take comparable photos to mine will need to spend as much."
This is a double edge sword to the uninitiated photographer-want-to-be. On the one hand, the price tag might discourage him enough to give up and go away. On the other hand, he might be just stupid enough to sell his Rebel and go out and drop $10,000 on a 1DX and a couple of L lenses. At which point the joke is on him because he'll be completely befuddled as to why he's still not taking great pictures.
And you sound awfully paranoid about competition.
I think attitudes like above are what somewhat give photographers a bad name (unfriendly, stand offish, cutthroat).
Or maybe he turns out to have not been a sucky as you think just because he was shooting with a Rebel and seemed to be relatively new and maybe in a few months he is handily out shooting you? And maybe he is loving his new camera because he loves sports photography and he ends up glad that he went from his Rebel + 18-135 to a 7D/5D3/1D4/1DX + 70-200 2.8 or 300 f4 or whatnot? Who knows.
Oh come one man, where's your sense of humor? That was meant as a bit of tongue in cheek. First of all, I have no competition. I only shoot for myself, family, and friends, and am lucky enough to have engaged with some fabulous mentors who constantly challenge me through direct and honest criticism of my work. I don't need to compare myself to anyone but myself.
As a matter of fact, I teach an adult education photography class several times a year in my community. I get nothing more than a small token payment for the effort. I do it because I enjoy passing on knowledge and experience to other people who really want to improve their skills. So if I was paranoid about any potential competition I wouldn't be basically giving it away.
But my main area of interest is portraiture. I don't know about the rest of the genre but the undeniable fact is that in the portrait arena, the streets are indeed flooded with mother-with-camera photographer wannabes who think they are the bees knees but couldn't produce a well composed, well lit shot if their life depended on it. But they think because they put that fancy DSLR in to one of the auto modes that they really didn't understand, and shot what was really a mediocre picture of their kid but one that all their Facebook friends "oohed" and "aahed" over, that that qualifies them to start passing out business cards. They go around selling cheap sessions for $100 with a CD of 100 images, depressing the market for the highly qualified artists who really do deserve the title. The real pro that has invested several tens of thousands of dollars in gear and many years of toil perfecting their craft are constantly defending their prices because a day doesn't go buy that they don't have to justify that higher price when "Magic Butterflies and Rainbows" baby photographer down the street, who just got a Rebel for her birthday, will shoot a newborn session for $50. And "Magic Butterflies and Rainbows" also hasn't paid any business license fees, isn't declaring her income and paying income and self-employment tax on it, isn't carrying equipment or liability insurance, isn't taking the usual precautions that a real pro would in having backup gear in case something breaks during the shoot, etc etc etc. So not only is "Magic Butterflies and Rainbows" basically giving it away, she is undercutting the working pros by not carrying any of the overhead expense that a real pro and legitimate business would.
Now, I know a lot of fabulous portrait shooters who started just like that. But at some point, they woke up to the fact that they had only taken one step on a journey of several thousand. So they buckled down and educated themselves, learned to use the gear they had to maximum effect, studied lighting, composition, perfected their editing skills, etc and in the end could turn out a really high end product. And I admire the work and the journey they've undertaken. Many of them are my friends.
My problem is not with them. It's with the other 95% of them that continue to market themselves as portrait photographers while simultaneously turning out garbage at garbage prices.
Every top notch portrait shooter I know who use to be able to earn a decent living in the business sees, experiences and suffers from this phenomenon every single day.