This happened with me once. I gave a reference, and after verifying me that reference contacted me and offered a discount. I declined, for a few reasons, kept the original plans and will never see the referenced girl again.
My reasons are...
1. I made arrangements with the new girl and feel an obligation to keep that. Just as it would piss me off if the girl cancelled our plans if she got a different offer.
2. I wasn't price shopping and never do. I don't clip coupons either.
3. I never told the reference it was OK to contact me and it is not ok that she did. If I can't trust her to be discreet or respect my privacy then I can't trust her period.
I doubt many guys would go for the lowball offer, and I doubt the OP wants to meet any guys that would do that. The OP is better off having been stood up.