Free: Contests & Raffles.
I seriously agree that you will find a great bike by looking at CL used bikes, by owner. Bikes just a few years old depreciate in price dramatically but have she same geometry and materials as current bikes. And look especially for bikes that have already been modified by knowledgeable owners. Lookmformdisc brakes, large tube diameter, at least 24 speed gearing. Front susoension is mandatory but rear suspension causes problems pedaling uphill - that means you want a ‘hardtail’. Here are a few I found in a 10 minute search.