Tile alternatives
Tiles are nice but not always affordable. Here are some ways to cut the cost.
Broken tiles
Broken tiles cost nothing and can be broken up and treated like mosaic pieces. To break them, hammer on the back of the tile. Mosaic pieces offer plenty of artistic possibilities, or can be something as simple as a 2 tone colour mix.
Pebble tiles
Pebbles make very low cost tiles, and can be stylish. They're available in various colours and colour mixes, and pretty colour mixes or patterns can be laid.
The downsides are a slightly uneven surface and a relatively high percentage of exposed grout, which is harder to clean than the tile surface. Size variation may cause wastage, and the tiling is quite a bit thicker than ceramic tiles.
Cement
Most tile adhesives and grouts are modified white cement mixes. For pebbled floors its possible to use unmodified (bagged) cement & silt. A £6 bag of white cement can lay an awful lot of tiles.
Unmodified cement takes a few days to establish any significant strength, so accelerator is required. The addition of EVA improves adhesion (often inaccurately called waterproof PVA).
Terrazzo
Grinding & polishing concrete gives terrazzo. Its low in material cost, but high in labour input. The result is beautiful. White quartz is the favoured terrazzo stone.
Terrazzo can only be considered low cost if you've time on your hands.