I've just emptied my both my work jeans pockets and the jeans I wore to Southend a few days ago and dug down the back of the sofa so I'm in a position to offer you £13.87 and half a packet of soft mints.
I think the most I've seen a very nice put together 'locost' type car go for is £7400 but that was SVA/IVA T'n'Ted and been on the rollers . As nice as your handy work is I'd say it's worth £5000-6000 on a good day but the fact that it's not been IVA'ed might put people off.