Cheapest, Fastest Infinity Terrain Ever?

When experimenting with expanding foam, I realized how effective it could be for Infinity, a game that relies heavily on terrain.

*This is a complete 4x4 table of LoS-blocking terrain for $16 (2x $7 foam cans, $2 craft paint.)
 *It took only an hour to make. (excluding foam drying time)
 *It has a coherent theme.

 

 It is very cheap. 

You get plenty of foam from a can. I actually have 4 more leftover terrain pieces I'm using for another project. (It will be a lava hell-world)

Sure, it isn't the usual omgwtfthisisamazing Infinity diorama, but for someone who prefers minimum effort and cost for maximum result, I'm pretty happy with my 1-hour + $16 investment.

The "palms clumps" were Chinese H0 railroad trees from ebay. You can see the MDF coaster they are based on.

Beyond the bare minimum....
*The trees were $10 for 30 from eBay and sit on 50c MDF coasters. However it adds to the cost.
 *Obviously you could add in foamcore buildings, but the investment in time climbs sharply. 
*Drybrushing the paint on the "cliffs", and adding small scattered gravel-sized rocks would improve it a lot.
*If you want to make the board mobile, you can glue the sand to the baseboard by painting it with 50/50 PVA/water mix. 
*You could easily adapt it using white sand and grey paint for a "snow" environment. 
*The whole sand table cost me $22 and 15 minutes to make.

As you can see, plenty of line-of-sight blocking terrain makes this a solid Infinity table. It would work equally well for Heavy Gear, Tomorrow's War/Force on Force or any game that requires lots of cover.

I'd welcome ideas for other cheap, easy-to-make tables. Put a link in comments?