Killer vintage 70's, 80's reel to reel to add to my setup.

before you buy any deck, better decide what tape format you are planning on playing. 

the Technics 1500 and Otari MX 5050 can cover quite a few. 

The killer king is Sony TC-880 (TC8750-2 Japanese version). Scarce spare parts as its original price. If you find one within your budget check it.

Open reels are old beasts, more likely they need servicing and calibration (can do for a specific tape you choose) so a very good and knowledgeable technician is your friend. Whatever you choose finding spare parts and easy maintenance should be on top of your list. Tapes are rather expensive but current production RMG are quite good. 2 track machines have the best sound quality and 4 track ones have the best tape economy.

Apart from mentioned Technics, nice looking and good sounding decks come from, Akai, Revox, Teac, Philips, Sony, Otari ...

Take your time and check, search, read.

Note, what kills them is not using them.

Happy hunting.

Thanks @petg60 @johnss @larryi @russ69 excellent out of the gate info. 

Tandberg made some outstanding decks!

Teac/Tascam made some nice semi-pro machines that go for not that much money.  Also, I think some Pioneer machines sounded pretty good, although their compact size did not allow for use of 10.5” NAB reels.