For Sheppard East, it may be sufficient to build a new bus-only bridge over 404, and then add a mixed-traffic express bus that reaches the east end of Sheppard. The capital expense will be under $100 million.
The new Meadowvale Rocket can run from Don Mills Stn to Port Union on weekdays. On summer weekends/holidays, it can run to the Zoo instead, and will be well used.
Money saved from Sheppard LRT, can be used to build two other LRTs in Scarborough, connecting STC to Centennial Progress campus, UTSC, and Malvern.
In 15-20 years, plans for the Sheppard corridor can be revisited. Hopefully, SmartTrack and the Relief line will be running, or in the final stages of construction by that time. Then, if the ridership forecast for Sheppard look better than now, the eastward and westward subway extensions can be back on the table.