We are not Parisians, but by applying some of our hard won small town France knowledge we have discovered some real bargains.
Eating for a reasonable price in Paris, particularly around the Grands Boulevards - that part of Paris "amenaged" so stylishly by Baron Haussmann in the 1870's - is very difficult. In particular the area around the Champs-Elysées can be a problem. We wrote in September about how moving just one block away from a main shopping thoroughfare can improve your chances of finding reasonably priced foods in London - and Paris is the same. Caffé Zaf is more than one block away from the Champs-Elysées, but only just (if you squint). It is one block away from Boulevard Haussmann. (I have it marked on a map here)
We ate here on our trek back from Australia after shopping on the Champs (as you do). For 8€ each I had a mug of lentil soup and a pastrami bagel, while Susan had a mug of the same soup and a smoked salmon bagel. This was followed by coffee and a macaroon. I will now repeat the price for the incredulous: 8€ each. That is 16€ for the two of us, which compares quite favorably to the $16 Australian (about 10€) for two coffees and one ciabatta at Sydney airport. What is more, whereas the ciabatta at Sydney airport was dry and flavourless, the bagels at Zaf were fresh, tasty and well stuffed with filling. (I know. It's a bit unfair to compare airport prices to anything on earth, but remember, Paris has a reputation for being really expensive).
It's not a Michelin Star dining experience, but it is more like what real Parisians experience for lunch, it is really good value and the procedure for getting a coffee is very interesting (I won't spoil it, I am not even sure I understand it!).
The church of St Augustine is just up the roadAfter lunch you can visit the Church of St Augustine which is about 200 metres away, and if you're really lucky they will be tuning the organ, as they were they day we visited. It isn't an old church (1870's) but it is grand - if in need of a clean.
On the topic of good value travel: I am a "destination expert" for the Loire Valley on Tripadvisor. I am, however, starting to question the value of forums where travellers give advice to fellow travellers. Far too many times on the Tripadvisor forum do I see people who have been to a place once or twice, giving advice on where to eat/stay/shop and claiming good value for prices that I would blanche at and no resident of a town would pay. Meals that I would pay no more than 10€ for are suddenly "good value" or even "cheap" at 25€: steack haché, moules, poule et frites. If you're travelling and want to know about value, ask a local, not a fellow traveller - their knowledge is most likely gained either from a book or another traveller further down the track.
This also means that places that you or I might look at and think "not bad" suddenly gain iconic status: Rue Cler is a place that no American worth their salt would miss on a trip to Paris, simply because it gets mentioned in a guidebook that Americans seem to rate above all others (and no-one outside the North Americas has ever heard of).