If the Price is Right

If the Price is Right is the first mission in the Deal ending of the storyline of Grand Theft Auto IV, it is given to Niko Bellic by Jimmy Pegorino.

Overview
Pegorino orders Niko to pick up the payment for a heroin deal, part of a partnership between the Pegorinos and Dimitri Rascalov. After many texts from Roman begging him to do the deal Niko accepts and comes to the conclusion holding grudges is stupid and so he goes with Phil Bell to the exchange point. Dimitri calls Niko to say that he has killed the buyers' representatives, and will keep the heroin for himself -- unfortunately, Niko and Phil are already in the buyers' compound. Believing they will not be able to escape the territory of the newly-betrayed buyers without a fight, the pair decide that they will steal the money. A massive gunfight ensues in the buyers' warehouse HQ, followed by a car chase when one of the buyers escapes with the money. They kill the dealer then take the cash from him; Niko then drives Phil to his hideout in Port Tudor and takes a cut of the cash.

Walkthrough
When Niko meets up with Phil from his apartment in Tudor he'll tell Niko that they are going to Port Tudor. Grab a vehicle and head over there. On the way Phil explains the plan. Dimitri is going to hand over the H to the buyers while they collect the cash.

Arrive at the exchange point in Port Tudor. Go to the exchange building down the street and watch another cutscene as Dimitri openly betrays Niko over the phone. Follow Bell onto the building's roof and destroy the skylight with Phil.

Jump into the skylight and immediately gain cover. The warehouse is crawling with goons. Use the SMG and Sniper to pick off some goons, then carefully go down the stairs eliminating any goons in sight. Continue on and gain cover. Eliminate a couple more goons and go down the stairs to ground level.

Gain cover behind the truck on the right and kill the rest of the goons on the ground. An assault rifle would be helpful in this situation. Jump over the scaffolding in the middle of the warehouse and go up another set of stairs. Cover Phil as you get closer and closer to the cash room. Once the area seems quiet, run down to the money room. Cutscene. A goon escapes with the money.

Chase the goon outside and ignore the big truck. Turn left and there will be a pickup truck and a dirtbike. Pick a fast vehicle from these two and chase the goon's truck avoiding the falling logs.

Shoot the truck repeatedly. Cutscene. The goon dies. Grab the truck and drive Bell over to Tudor, where he will give you a large slice of money and a debriefing cutscene.

Niko receives a $250,000 cut from the deal. Roman is happy that Niko has seized such a fortune, and that he has put Dimitri's betrayals behind him; Kate, however, is not happy that Niko took money, and refuses to come to Roman's wedding.

Trivia

 * The name of the mission is a reference to the famous television game show The Price Is Right which is the inspiration for the GTA series logo font.
 * This is the second time Dimitri betrays Niko.
 * The $250,000 you receive after the mission is the highest reward you can get in the whole GTA IV Era. (Three Leaf Clover and Out of Commission also have this).