Compare in a single controller two models

Question

Hello, I have to make an auction website and in Users_Offers I need to make sure that they don't bid less that "Start Price"  from Auctions

 

 

 

 

This is the controller , but when I run the application the "oferte.Licitatie.PretInitial " ( which is Auction.StartPrice ) is null and I get an error "Object reference not set to an instance of an object."  I tried to write it like : db.Auction. but then StartPrice doesn't appear anymore.

 

 

 

public ActionResult Create([Bind(Include = "Oferteid,IDLicitatie,IdUser,ValoareBid,DataBid")] Oferte oferte)
        {

            if (ModelState.IsValid)
            { if (oferte.Licitatie.PretInitial < oferte.ValoareBid)
                {
                    db.Oferte.Add(oferte);
                    db.SaveChanges();
                    return RedirectToAction("Index", "Licitaties");
                }
                else { ViewBag.notificare = "Trebuie o suma mai mare decat pretul initial"; }

            }

            ViewBag.IDLicitatie = new SelectList(db.Licitatie, "IDLicitatie", "IDLicitatie", oferte.IDLicitatie);
            ViewBag.IdUser = db.Useri.FirstOrDefault(x => x.Email == User.Identity.Name).IdUser;
            return View(oferte);