Yamaha's Reface series brings back classic sounds in mini keyboards with speakers even as well as MIDI so they can be played from full sized keyboards.

Reface CP - Electric piano sounds ( plus a hidden acoustic piano patch )
Reface DX - An FM sysnth with improved patch programming UI over the original DX synths
Reface CS - Analog modelling synth

And they are less than $300

https://usa.yamaha.com/products/music_production/synthesizers/reface/index.html