For value-conscious travelers, flying business or first class is increasingly within the realm of possibility. Prices for these seats are lower than in the past, said George Hobica, the founder of the air travel advice site airfarewatchdog.com. “Airlines used to upgrade passengers to first or business class for free,” he said, “but they’ve stopped doing that and are instead making these tickets more affordable and attainable.” Here, he shares his tips on how to snag a seat in these premium cabins without paying premium prices.  BUY DIRECT The airlines themselves, as opposed to third-party airfare ticket sites such as Expedia.com, usually have the best prices for their business- and first-class tickets, Mr. Hobica said. The lowest rates in these classes tend to be nonrefundable. So when searching for fares on an airline’s site, find the cheapest options by searching for a nonrefundable first- or business-class seat.  Also, know that carriers often have fare sales for these cabins in the summer and over the December holiday season, when fewer business travelers are flying. Find out about these sales by signing up for an airline’s e-newsletter. One example for this year: British Airways has Thanksgiving and Christmas specials where passengers can buy tickets in first class or Club World, the carrier’s business-class equivalent, to London from some cities in the United States starting at $2,038.  FOR INTERNATIONAL TRAVEL USE A CONSOLIDATOR Airline ticket consolidators buy in bulk from airlines and sell them to consumers for a discount. It is even possible to find these fares for last-minute travel. Mr. Hobica said he frequently buys tickets through consolidators to fly to Europe during the peak summer season for prices equivalent to or within a few hundred dollars of an economy ticket on the same flight. However, be aware that you might not earn frequent flier miles through a consolidator ticket, and the ticket may be nonchangeable. PlanetAmex.com and InternationalTravelSystems.com are both reputable consolidators.  TRY A LOCAL TRAVEL AGENT That brick-and-mortar travel agency in your town could have access to consolidator fares, Mr. Hobica said. Though many travel agencies can no longer get you discounted airfare, there are some who can, he said, and it’s always worth calling or stopping in to find out.  UPGRADE WITH MILES Airlines sometimes offer to upgrade your economy ticket for a nominal fee combined with frequent flier miles (usually with 15,000 to 20,000 miles each way for travel within the United States and at least 40,000 miles one way for international travel). For an additional $75 and 15,000 frequent flier miles, Mr. Hobica said, he was able upgrade a $133 economy ticket to Boston from Los Angeles on American Airlines to first-class.  A version of this article appears in print on October 16, 2016, on page TR2 of the New York edition with the headline: How to Find Deals on Flight Upgrades. Order Reprints| Today's Paper|Subscribe
To find affordable business and first class tickets, buy direct from airlines — and upgrade with frequent-flier miles.