Another place to look for information on discount rose bushes is through wholesale garden magazines. Local libraries would have information on any trade newsletters and magazines that would contain catalogs for discount rose bushes. Advertisements in trade magazines for nurseries may contain information on dealers of discount rose bushes.
Many retailers will only sell discount rose bushes to businesses and nurseries. There are, however, retailers who offer discount rose bushes to both public and commercial markets. Many retailers may not offer actual wholesale prices to the general public, but will make deals for rose bushes bought in quantity. If a company or nursery will not offer discount rose bushes to the general public, always ask if there is a price break for ordering in quantity.
One other option would be to wait until the end of the prime planting season and contact local nurseries. The nursery may have overstocked several varieties of rose bushes, and may be more than happy to sell the remainder at wholesale or discount prices than simply throw them away and lose money.