I am on a bit of a terrain kick. I had some very cheap doormats from IKEA, which set me back a whopping $10 per mat. I had just cut them up and spread them around, but the colour still annoyed me. They were still too doormat coloured. So they looked like cut up doormats. I bought some different spray cans from Bunnings, one Golden Yellow and one Sandbark, plus I had some Almond left over. Then experimenting with all three got a wheaty shade that I liked. You really have no excuse to create your own inexpensive wheat fields using cheap doormats. Personally I would rather stick a fork in my eye than go to IKEA, but they do have some good sources of modelling materials.
I also made some new rough rural stone walls to line my country lanes. Super cheap source of small stones from Bunnings at around $4-5 per bag. One bag and its enough rocks for hundreds of metres of wall. I just PVA glued rocks in line on top of each other onto MDF bases. It requires a bit of patience as you need to go away and leave the layers of rocks to dry before adding a new layer. A black spray and then increasingly lighter dry brushing with grey and brown is all you need. I flocked the edges with some grassy green and hey presto. Another very cheap addition to your table. Quick and easy and no need to go spending dollars on rough stones walls. They should be rough and rural!