Good Cheap Terrain - the Solution?

I've made a new resolution: to force myself to spend 25% of all wargaming outlay on terrain.

I currently have minis and rule systems lying unused as I have no suitable terrain.  It's like having 5 cars with garage space for 2!

Since playing with a sheet stretched over books and using shoebox buildings lack appeal, I considered my options:

Scratchbuilding. This has little appeal as I prefer to spend time painting the lead mountain.I have had some success with 5mm foamboard in whipping up lots of Infinity terrain. There are plenty of tutorials out there and Matakishi's Teahouse has some inspirational stuff. 

Resin.  Prohibitively expensive for 28mm, this is my preferred 15mm option. I like the stuff I got from JR Minis.

Paper or card.  Flimsy, unpleasantly 2D, hard on ink cartridges/or/surprisingly expensive to have printed. The WWG stuff is rather nice but given the effort, scratchbuilding is probably an easier, cheaper option. Terraclips shows some potential and I am awaiting my long-delayed order. 

But I may have found a solution. When reading Combat Zone (a funny and informative look at scratchbuilding) I came across this from Sarissa Precision. MDF! Yes, the cheap stuff from the local hardware stuff you usually see as the gaming table base.

The Old West stuff, being wooden, appealed to me most. With a wood stain you may not even have to paint it! 

Not only do they do hotels, churches and specialist buildings - the range includes 28mm and 15mm WW2/moderns such as this:

Pros:
Pricing is literally half that of resin. 
The laser-cut mdf has the same detail as resin. 
Buildings can be snapped together in 22 sec and store flat.

Cons:
Warping?

I'm putting in an Old West order - finally my Black Scorpion Tombstone minis and Legends of the Old West rules might get an airing.  If they are good, I'll order from the modern range.