If you think it's impossibly expensive to travel in France, think again. In the last week of September we found it easy to travel in Province and the Cote D'Azur, staying at hotels suitable for adult couples -- not just spartan students -- for anywhere from $16 to $40 a night double without advance reservations. And the tab for an enjoyable dinner with wine at a local restaurant in cities like Vienne, Orange, Nice or San Raphael usually ranged from $15 to $25 for the two of us.

That's not pennies per day, but it's certainly no more than you would pay for a similar trip in the United States and not the horrendous figures you often hear cited as the cost of a trip to France.

After attending an education conference in Paris, we planned to get on the road and tour the Roman cities of Provence, then Nice, Cannes and others on the Mediterranean seacoast.

This area is filled with magnificent remnants of Roman civilization in Southern France during the first and second centuries -- like the giant coliseum in Orange (seating 8,000 and now being used as an outdoor theater) and Nimes (seating 20,000 or more and being used for bullfights). This is the countryside painted by Cezanne, Van Gogh and Matisse, and it actually still looks the way they painted it.

We found you could rent a Renault 5 (called Le Car here), a peppy little car quite adequate for two middle-sized people, for about $250 to $325 a week, unlimited mileage, at Charles de Gaulle Airport or at numerous rent-a-car stations in Paris from National Car Rental (called Europcar there), Avis or Hertz. The price includes tax and you can use your American credit card.

We got ours from Europcar and the price was 1,029 francs, or about $250, including insurance, tax, etc. The franc is worth a bit under 25 cents. You start with a full tank and buy your own gas after that (it's about $3.50 a gallon, but the car gets over 35 mpg on the road so it's not so bad). Getting on the big national toll highway ("the Peage") you can make Lyon in about 6 1/2 hours. Below Lyon, we switched to local highways for sightseeing in Provence.

We were armed with a brochure listing hotels in every town (Hotels in France, French Government Tourist Office, 610 5th Ave., New York, N.Y. 10020) and it was a good security blanket, but we found we didn't need it. At our first stop, the town of Vienne, a bit below Lyon, we went to the first hotel on one of the main streets.

The Hotel de la Poste was a modest, quiet place. Yes, they had a room for 65 francs (about $16) with toilet and sink (shower in the hall), but they insisted that guests eat dinner in the hotel dining room if they wanted the room. That turned out to be fine. For 43 francs apiece, plus 9 francs each for a bottle of wine (a total of $26 for the two of us, tip included), we had a fine meal in their stately dining room -- pate, soup or salad for the first course, broiled pork cutlet with baked tomato and a big plate of roasted potatoes for the main course (there were several other choices), wine and cheese. Breakfast the next morning (coffee, croissants, bread and jam) was another 11 francs ($2.75) each. American credit cards accepted.

The next night, in Orange, we paid 160 francs ($40) for a room with toilet, shower and bidet at the Hotel Arena, including breakfast the next day. As in Vienne, we simply walked around near the center of town for a few minutes until a likely looking hotel.

Other prices per couple:

At Pertuis (just north of Aix-en-Provence) Hotel "4 Sept.," 95 francs ($24) for a room with bath and bidet; breakfast extra if wanted. At Nice, Hotel Astoria, 85 francs ($21), included sink and bidet; this was only a few blocks from a huge restaurant and shopping stretch in midtown, with outdoor restaurants open late into the evening. At St. Raphael, a seashore resort, Hotel Pastorel with toilet and shower, 120 francs ($30). Nimes, Hotel Nemausa 96 francs ($24) including breakfast, shower, bidet and sink.

Not all these hotels had a toilet in the room, but with a bidet and sink you can usually get along, and the toilets and showers down the hall were usually, to our delight, spotlessly clean. The rooms themselves were also clean, with good clean linen. The more toilet and bath facilities that were in the room instead of the hall, the higher the room price.

The highest we ever paid for a meal was about $30 for two. At St. Raphael, we walked into a small restaurant and had a superb couscous for 45 francs ($11.50) each. Obviously, we didn't go to any Guide Michelin restaurants, but every restaurant we went to (picked out by chance on the street) was quite adequate. For lunch we usually bought bread (about 40 cents) and some cold cuts and cheese (maybe $1.50 total) and some Perrier (up to 75 cents a bottle) or wine ($1 a bottle) and ate in the open.

All this, of course, does cost something. But it's nowhere the $100- to- $150-a-night stories you constantly hear. Incidentally, even in Paris, where we stayed with friends before starting our tour of the south, we saw some respectable looking hotels for prices of 168 francs ($42), for a room for two, just a few steps off the Place de Gaulle (Arc de Triomphe) and Champs Elysees.