well it's hard to tell the exact size here. but I Bid something similar in size and scope this past spring and lost it, I was $17 per unit... have no idea what the guy under bid me with.
My advice is, if you want it, never bid a round number. go $19, not $20.
or even $19.50... most people will figure or look to round numbers (like 20, 25, 30) So if you come out to a round number, dip just underneath it.