I need some ideas. I need to be able to run a 50 watt light bulb for at least 5 hours, everyday, cheaply (on the road)?

If you're "on the road" we have to assume you have a vehicle of some sort. An ordinary halogen headlamp is about 50 watts (at 12 volts). You can run them all day and all night. I don't see the problem. If you're trying to ask about some other sort of 50-watt bulb, feel free to edit and update the original question, so we can all try to give better answers.

get a good car battery and wire a 50 watt led equiv. light to it and get a solar trickle charger

If it HAS to be a light bulb

use an LED bulb

and something like this (under $150)

https://www.amazon.com/ISUNPOW-Portable-Generator-...

If you don't need a bulb

that is: if you can use any car-rechargeable or sunlight-rechargeable battery-operated light source

then it will be much cheaper

and you have tons of options, see Amazon or Google Shopping

easy to find car-battery to wall-plug power inverter .....................

"New Cheap 200W 12V DC to 110V AC Modified Sine Wave Car Power Inverter Converter"

im sure theres a rechargeable LED light that has a car 12v charging adapter .. im not going to go search amazon for you lol