The short answer to affording moulding like that is...you buy 2000 feet at a time a few times a year just ahead of shows, fairs, institutional jobs, and the holiday season. Which means you better have very high confidence in your framing choices and your artwork based on market testing! And a good sense of when more dollars spent will not bring increased returns. And lots of storage space and a good back. And efficient framing tools, in which I have more money invested than in photographic equipment.
With volume buying, the frame in my picture probably cost me right around $100 for frame and liner, which I cut and joined myself from box quantity full length sticks. If I had bought the same combination in single units chopped to length by the supplier, that would be about $450+, and there are some intermediate possibilities as well. But bottom line...I build the frames myself. At the end of the day the piece comes in at a cost that puts it at a price point that is hard to beat for the type of work. I'd want to see that one go for around $900 minimum in a gallery which is a price that endears me to gallery owners and buyers alike.
I also sometimes do large pieces framed in polystyrene moulding which costs relatively nothing, and is profitable as low as $400 to $500 in appropriate venues such as art fairs and hotel lobbies. And there's a lot of polystyrene moulding finally finding its way into nice galleries. Attitudes towards poly have changed a lot recently as wood moulding prices have soared and quality has plunged. Note that almost all polystyrene moulding is crud, but there are a few remarkable exceptions.
Of course you could simply become a very famous artist and farm the whole thing out and sell your pieces for $20,000 each. But there is a far more certain but work-oriented path to photographic survival that entails courting the kinds of middle-range markets that I pander to. Your chance of success there is about 1000 times greater. But it takes work, and possibly some pseudo-Calvanistic determination.