Back up monitor went out

Those 7" CRT B&W monitors are very easy and simple to repair
Being a CRT and mono chrome to boot its most likely not worth the repair costs unless you do it yourself
Yes a color TFT/LCD will work fine with a B&W camera
No need to change the camera unless you want a color view of what's behind you

I'd love to repair it myself but I don't know who has the correct CRT and unless it just plugs in, the soldering might be dicey. I'ts also hard to understand why these things are priced between $300 and $400. Maybe I just haven't searched enough. Thanks for the reply.

They are priced at what the market will bear - NOT what is costs to produce
Made in China and might have a total cost of production of $25.00 or less

Chances of the CRT being defective are VERY low - check out a TV repair shop
Yes soldering will be needed for proper repairs