First off, I hope you don't live in the USA because that unit specifies 240VAC, 50Hz and we run 120VAC, 60Hz.
Second, there is nothing nice, unless the TT is (I did not take time to research and I am not a vinyl guy).
Third, consider the Cassette player worthless, it was never good quality.
Forth, Sanyo made some decent cheap components, but they never made anything worth getting excited about.
Fifth, unless the speaker surrounds have been replaced, it is almost certain to need them.
Sixth, the Sanyo system came with Sanyo speakers. I would have some concern that the Sanyo electronics may not be properly tuned to teh Coral speakers (which is a brand I don't know, but I never heard a speaker from Japan in the 70's that could compete with USA or European speakers. They got better later, but while Japan captured the market on electronics, they lagged behind with speakers (IMHO) in this era. Technics and Sony were just starting to get decent in the late 70's. I have no idea what vintage the Coral speakers are, I have never heard of the company!
Did the seller state everything worked properly?
I'd be very impressed if it did! I would guess that unit to be around 45 years old and expect there to be lots of "scratchiness" when adjusting the volume. Also rubber (as used for belts in the TT and cassette player drys out and shrinks over time) This was not a very expensive system when new and it would be unusual for anyone to spend the money to overhaul it as opposed to buying something new.
IMHO, the only thing it has going for it is it looks kind of cool in a retro way.
Personally, unless you have lots of information on the system to know it is in perfect condition, I would get out while I can!