If you have a computer next to the layout, SPROG is an option.
For about $90 plus PC or laptop, you are JMRI, WII Throttle, good programming options, etc.
This gets you started.
You can switch tot he more expensive systems later if needed, and you can still use SPROG and JMRI as programming station. (The Digitrax WiFi uses the same interface as JMRI, you just pay for it more)