Looks to me like he is asking for near new prices on most of it. Plus, a lot of it is vague.
Here are my thoughts/questions:
Mash Tun - What is it made out of? cooler, keg, pot? how big? false bottom or manifold, etc.
HLT and Boil Kettle are both aluminium... not sure how much the spigots add but seems a little steep for used. Plus, how big are they?
3x 5 gallon buckets $30... $10 for a 5 gallon bucket?!?!?! You can get them at Lowes brand spankin new for $3. Brew shops sell the 6.5 gallon new for $11
Burner $50 - you could probably pick up a cheapie turkey fryer burner at walmart with the aluminum pot for $35
immersion chiller - how long? what is the od?
5x Better Bottle Fermenters $125..... you can get 6 gallon BB on amazon for $27 each brand new. If you do 5 gallon batches, it is nice to have the extra head room in your fermenter for your yeasties to go crazy. Or you can get the 5 gallon BB for $20.
2x Corny Kegs $100... pin or ball lock? I can get pin locks for $35 each from my local brew shop. You can get them for around $40 from online retailers iirc.
I would pass up on this deal personally unless you like the convenience of getting it all at once.
my $0.02 that aren't worth a penny