Based on the financials, LD revenue would half to roughly double to match operating expenses. Do you really think it is as simple as Amtrak just doubling average ticket prices (and other revenue sources) tomorrow? If so, why hasn't Amtrak done that already?
Here's where we get into
Revenue Management which Amtrak does not do very well at all.
The
Bucket Charts that you see here every so often are a reflection of archaic practices in the industry, partially due to regulatory burden and partially due to a lack of investment in revenue management.
If you were to double prices, you'd probably outright kill utilization. What Amtrak should be doing is experimenting with raising prices on selected routes/configuations based on internet searches, interest, booking patterns, etc. Right now the buckets are (presumably) set somewhat manually and in advance. There's a certain number of low bucket seats, then once those are sold they roll to the next bucket, etc. Looking at the bucket charts, you can see these are being adjusted periodically.
However, airlines do this algorithmically. Airlines will, upon sensing more interest in a route (say because of some conference announced somewhere), will immediately raise prices to whatever they think someone will pay for the seat.
Airlines also aggressively discount open seats to fill planes, as well as have good data to predict when people will purchase last minute seats. Amtrak does not.
Airlines will also offer seat upgrades when available. Amtrak does not (at least not widely in practice. Guest rewards members have upgrade coupons, but I'm not seeing where they'll offer discount roomettes to coach passengers or offer to upgrade roomette passengers to bedrooms to increase revenue.)
Amtrak also has the problem of many connection options that it has not learned to optimize. On the CZ for example, you can get a roomette from Denver to Granby. However, that might prevent someone from buying a roomette from Chicago to Emeryville.
The cost of just adding another sleeper car is also not feasible on LD routes under the current rules. If there's more demand between Denver and Salt Lake for the holidays, a train still has to lug the car and SCA from Chicago to Emeryville and back.
The idea of 3x weekly service is to cut operating expenses to meet passenger load.