I hunt alone and have pretty much given up crossbow hunting over leaves from too many deer lost to lack of blood trail (and they just don't taste the same if found the next morning).
I've been thinking about buying a night vision monocular that would help me find my deer.
I called a reputable company that sells everything optical and they said I wouldn't be happy unless I spent $2,000 on a FLIR Scout PS -24 Digital Thermal Imager. I would greatly appreciate any opinions.

Sounds like you shouldn't be hunting at all! Leaving a deer to rot after it spends a night without being found, because it "tastes bad" is pretty flucking lame!!
Blaming it on leaves on the ground is also pretty sorry. It sure seems you do not know where on a deer to aim and when to shoot.
Night vision optics are not going to cure those issues! In my opinion you need to get you act together or quit hunting!!

What I said was the deer don't taste the same, never said they tasted bad or left them to rot.
Now that I have been on 4 different forums for a while I am hearing from others not afraid to tell the truth that this loss of tracking blood in bow hunting, even with good solid hits, is not unusual.

OK Beetle,I'm going to pretend you are a real hunter and not just an anti trying to start something.First what are you shooting?Which broad heads?Where are you aiming?How far do you track the deer?How many have you lost?Who taught you how to hunt?

oh sh*t... here we go....

Tell em to chill out, lots of info is needed to determine why you are losing deer [B]number 1 is your age and eyesight, how long did you wait after the shot,what kind of woods. etc
where are you aiming, is your bow accurate,and who did you learn from. give these guys the info they will help you. This site has the most knowledge about crossbows and hunting.

Hate to say it but it looks like I may have been correct.It doesn't seem that he/she really wanted an answer,just how bad hunting is.

The reason to go with a FLIR type is that it will show you the game clearly based on it's own body heat, while a light intensifier does not, just lets you see better.

But that is a LOT of $$$$ to pay. I'd just stop taking late evening shots if in your situation. Early morning would be good to go as would the rest of the day.

Another possible help would be to go to a razor head like the Spitfire or Grim Reaper that give very large cut patterns and will put the deer down quicker.

I hope some of this helps.