In the last 20 months I have built a new bigger and better 24' x 26' x 9' garage, blown in insulation, new windows (same company I see for my rentals the upgraded model), new siding and paint, wrap around deck, new driveway, drain tile and sump pump,  added a basement bathroom and finished the basement.

Perimeter space is the most valuable and it's being used for lower value features.The party walls can be insulated with either cement block or staggered studs with double drywall and resilient channel.

A new furnace and insulate building could change all of that.

I suppose as long as you get a good buy, you are somewhat insulated as the starter home buyers market in SF (as you noted) is still probably secure. - are you noticing less competitors on the buy side from other local rehabbers?

Homes built today also include many more expensive things like dual-paned windows, energy efficient roofs/water heaters/appliances, insulation, safer electrical and plumbing, garages instead of carports, etc.

Repaired a very buckled foundation, poured a new slab floor, demo'ed entire first floor, new insulation, new drywall, new electrical and plumbing, flooring, trim, kitchen, bathroom, appliances, paint, new exterior door, new interior doors, new windows.

I would have been fine with doing some reasonable upgrades in the space to be redone and some minimal-impact work elsewhere but I was not about to gut the entire building to upgrade all the insulation and firewalls and add a sprinkler system which is what they wanted.   

We often hit 20 degrees below zero and trailers are not properly skirted or insulated, or at least have heat tape on the pipes they can freeze up and cost you lots of money. 

They have now added energy requirements to the code (not sure if Aurora follows this but I know Denver does) so if the walls are not adequately insulated you have to insulate them and if the windows are not adequate then you have to replace them.

Gutting that one down to the studs and completely rebuilding it - new drywall, windows, insulation and all - first time I've completed something so major - about at the halfway point and excited to see it when it's done - near Central and oliver.