I have the best solution ever! Well i'd like to think so. This is what you do. You put the nikkor up for sale, but for a price nobody would ever pay you paid $140 for the two correct? EXAMPLE: sell the nikkor for like $150? $100 even then you would have gotten the sigma for 40 bucks! If somebody happens to buy it, sweet, if not, then you got yourself 2 lenses. Worth a shot IMO. GOOD LUCK!