Frontier Airlines has changed the airlines’ pricing tiers and is now offering economy and Classic Plus ticket fares. Classic Plus, fully-refundable fares, are more expensive and include a free carry-on and checked bag, advance seat assignments, stretch seating, no fee for flight changes and priority services at the airport.

If you choose an economy fare, you must pay a fee even for a carry-on bag, ranging from $25 upon point of purchase at FlyFrontier.com, up to $50 at the airport gate, along with various other fees for seat assignments and itinerary changes.

Frontier EarlyReturns members who opt for a Classic Plus fare will get 150 percent elite qualification miles compared to 100 percent for those who purchase economy fares. EarlyReturns Summit and Ascent elite members get most fees waived.

Frontier travelers can also choose to join Frontier’s Discount Den, where they will save $5 off every carry-on and first checked bag fee, bringing the first checked bag fee down to $15, which is cheaper than a carry-on at $20. And everyone on your same reservation will get the savings. Membership in the Discount Den is free for EarlyReturns members through June 30, 2015. Along with savings for your bags, as a member you’ll get special offers and priority discounts not available to non-members (be sure to opt in for email alerts to receive information about the special offers).

After the Discount Den trial period that expires the end of June 2015, Frontier will assess the benefits and begin to offer Discount Den memberships for a fee. The fee amount has not yet been determined.

Bottom line: It looks as though the new Discount Den is similar to Spirit Airline’s $9 Fare Club that offers flight discounts and reduced bag fees for the member and flight companions. The annual fee for the $9 Fare Club is $59.95.

To give you an idea of the cost of a Classic Plus fare compared to an economy fare, we searched for a flight from Denver to San Francisco in August, departing on a Friday and returning the following Wednesday. The Classic Plus fare outbound was $228.99 and the economy fare on the same flight was $148.99; the Classic Plus fare inbound was $188.99 and the economy fare was $108.99. So, the total savings for an economy roundtrip fare was $160. If you added in the cost for one checked bag and one carry-on bag, that savings would dwindle down to $120 ($15 checked bag with a Discount Den membership and $25 for a carry on bag), but still a significant savings.