This is going to work similar to the way real government contracting works, you bid how much you're willing to complete the project for, each bid should go down as the cheapest bid will win the auction. Here is the list of materials we are buying:
3336 spruce slab
3049 birch planks
1304 black glass panes
1048 stone bricks
911 cyan terra
709 smooth stone slab
626 stone brick slab
608 spruce planks
531 green terra
462 white glass
443 andesite slab
422 oak leaves
372 cobble slab
371 bricks
337 smooth stone
295 spruce fence
188 terracotta
166 polish granite
136 birch slab
123 white panes
123 lantern
122 dark oak leaves
119 brick slab
107 stone brick wall
64 glowstone
Starting bid: 7,000
bids must go down by at least 50
auction ends 24 hours after the bid of the last bidder
you will have 1 week from the end of the auction to fulfill the order.
3336 spruce slab
3049 birch planks
1304 black glass panes
1048 stone bricks
911 cyan terra
709 smooth stone slab
626 stone brick slab
608 spruce planks
531 green terra
462 white glass
443 andesite slab
422 oak leaves
372 cobble slab
371 bricks
337 smooth stone
295 spruce fence
188 terracotta
166 polish granite
136 birch slab
123 white panes
123 lantern
122 dark oak leaves
119 brick slab
107 stone brick wall
64 glowstone

Starting bid: 7,000
bids must go down by at least 50
auction ends 24 hours after the bid of the last bidder
you will have 1 week from the end of the auction to fulfill the order.