We have a couple of ex-display folding bike ramps going cheap! Normally $239, now $175 for the black and $140 for the red which has faded in the sun. These can handle 225kg (500lb), are made out of aluminium alloy and fold for easy transport.

The red one for $140:
https://www.trademe.co.nz/Browse/Listing.aspx?id=1532290535

The black one for $175:
https://www.trademe.co.nz/Browse/Listing.aspx?id=1532292142