Cheap fibreglass

Sorry if this has been asked before, I'm new here. I'm looking to make my own seat and sidepanels, maybe even a tank if I don't prove to be useless, but being terminally skint I need to find a cheap source of fibreglass supplies. I reckon it'll be better for me to try to make a seat from scratch than to buy one and modify it to how I want it, but I've no idea where to buy fibreglass from other than fleabay, and that looks pretty expensive.

Also, I'd appreciate any advice on what type of matting to use, resin types, thicknesses, etc, as I've not tried anything like this before. Should be fun trying though...

 

Don't expect anything too exciting. I've spent all my biking life putting bikes back to standard, this'll be my first go at modifying one. Anything could happen...