Thank you for submitting your item for appraisal. This appears to be a 1940s Paris street view painting by an unknown spanish artist with the name ( or using the pseudonym) Rusinol. The Arc de Triomphe and the Avenue des Champs-Élysées are favorite motifs among painters working in Paris. Another painting with a similar motif by the same artist was offered recently, but no auction results are known. Just for the motif it is an attractive painting, which should be able to ward off the competition of cheap chinese knockoffs from Dafen.
The estimate is based on similar older paintings offered or sold at auction, "asking prices" in the trade might be higher and vary.