Sometimes you can get bulk tickets from a wholesaler that has a large group trip in town. The Aspen airport closes for resurfacing on 4/9 and I heard that the ski co drastically reduced prices to draw some groups in for the last week. You might also check with your hotel, maybe they can get some?
The skiing was good last week and they decided to keep Highlands open until 4/8. Bell chair is also open until 5PM if the weather is good.
The Front Range stores have not offered discount tickets in grocery stores locally for several/many years. They only sell the picture Classic Pass now and that is usually at the beginning or before the season starts. Your best bet is to find a Roaring Fork local with a picture pass who can buy discounted tickets for you. Or perhaps offer to buy an employee a nice dinner in exchange for one of their comp's?
Walk into the rental shop and ask the techs what they'd be willing to trade for some of their comps. Most employees with comps left in April don't mind trading them for something. Generally employees get in trouble if they trade comps for cash, but who knows.. maybe at Aspen they don't care so much.
You could probably arrange this before you even go there. Just call the toll free number and speak with the guest services agent.
Things I've gotten in the past for my comps: new helmet, roundtrip voucher for Southwest Airlines, jacket, etc.