I don't believe he's looking for friendship. Men often say that if they feel there's a chance to wear you down for a date. I'd be wary if he knows you own a condo. He might give you a sob story about being evicted, losing his job, etc., to move in for free rent. You'll never get rid of him.
It used to be very hard for me too. It takes practice and a few times of being taken advantage of to kick your instincts to protect yourself into permanent high gear.
I don't believe he's only looking for friendship either. What gives me caution is this indirect way of asking you out and also it's insulting. Taking someone out for dinner to test the food before you take someone else out is already putting you one down.
IMHO, someone who wants to take you out to dinner will ask, directly. If he cares about you, he wouldn't make this comment, he'd know the restaurant was a good place. It does sound like he's joking a bit but on your part, if you accept a less than acceptable place to eat, he then knows you accept less than kind treatment. By acceptable I don't mean it has to be an expensive 5 star restaurant but some place he's been and likes and thinks you'd like it too.
"There's a great Mexican restaurant nearby- want to go get something to eat sometime?" is a casual, yet direct way to ask.
Someone who respects your boundaries wouldn't push the "no thank you" to his dinner invitation. That he keeps pushing it, tells me he doesn't. I don't think he's a good choice for a "just friends" either.
Seeing what you don't want here can also start you thinking about what you do want in a potential friendship or relationship. Direct and clear communication, respecting boundaries, to name a few.
Imagine you meet someone who you would like to get to know better? And he asks you to dinner, directly.
I'm not single but if I were, I wouldn't go anywhere in someone's car or accept a dinner invitation right away from someone I don't know well. I would reply, directly- I'd like to get to know you better but I prefer we meet for coffee first. If he respects that boundary- pick a place, drive there with your own car, and it's coffee only until you have checked him out, and feel you know him better.