This lovely Roseville vase I own was made in the 1940's, it is called White Rose Double Cornucopia. I bought it on E-bay for around $35, it had a small crack on the inside, so I was able to get it for a better price. If it was in mint condition, it would be worth around $200! I bought it just because I liked the look of it.
Roseville pottery was founded in Roseville, OH in 1892 and moved to Zanesville, OH in 1898, they closed the factory in 1954. In the beginning they were producing high quality pottery. At around 1919 they began producing more affordable pieces that became very popular. These pieces are now very valuable to collectors. There are fakes out there, as with many popular collectibles, so you do have to be careful what you buy. You can find pieces to buy from antique stores to E-bay, so they are easy to find, but some pieces are more rare.
I like the soft colors found on most pieces of Roseville pottery and the unusual designs of each piece. If your looking for a nice antique collectible I would recommend Roseville.