Plaster fillers for basing. I use the Powder filla as its economical. $8 for 500g.
Coloured primers make painting easy just wash with a pigment wash for effect.
Super Glue from GF9 you get 28g for ~$12. Hobby super glue dries slower but joins with a slightly flexible bond for longevity. Much better value compared to most bottled commercial brands where you get 5g for ~$10.
PVA wood glue which dries clear is perfect for all things basing rocks and flock. Selley's is top quality and you avoid peeling and weak bonds of cheaper pva glues.
Woodland Scenics do a superb range of grasses and flocks. Heaps more economical too.
Contact adhesives for all that terrain making. Here's my choice.
Matte sprays to take the shine out of your masterpiece. This is what I use.
Green Stuff from GF9. Two tubes which is about 10 times more at the same price of some brands.
I use magnetic paint for my bases. This provides a easy to apply (3coats) surface that magnets will adhere to. Magnetic sheets are readily available and we currently get them from a commercial place in the North Shore. Just zap me a message if you want to get some and I'll give you the deets.
Ran into a brilliant tutorial on cheap tree making which I had to share. Tree's are the most expensive terrain pieces but this vid really makes it look good at a reasonable price.
I think these are a goer!