Are we talking separates as in Pre + Power + Tuner here? Or just an integrated amp?
As many, I own TOTL receivers (Concept 16.5, Yamaha CR-2020) as well as TOTL separates (SPEC 1 + 2 + TX9500ii). I don't want to venture into what sounds best - they are hooked up in different rooms, with different sources and different speakers. Besides, my ears are far from audiophile quality in the first place - I just plain like the old stuff!
Now to my point: I am not certain I fully agree with the notion that separates are soo much cheaper. Except for a few extremely rare and/or collectible receivers (1980, 2600, 3020 spring to mind) I believe that one can purchase, in the open market (e.g., eBay) a whole slew of TOTL or near TOTL receivers (100-170 wpc - e.g. SX-1250) for mostly under $1,000. I welcome you to find TOTL separates (pre, power, tuner) in this output range (e.g., SPECs) for cheaper when adding component prices and shipping - please let me know when you do!
In short, I believe that comparable separates and receivers are priced at similar price points.
Rgds,