For $1-2K I would recommend a Juno 60 (single osc per voice with chorus) or a Prophet 8. It depends what you want though.
However, from just over $2,000 you are in range for a Prophet 12 keyboard, which is virtually alone in the field of what it can do. The keyboard action is beautiful, build quality solid, and the keyboard layout is so intuitive and easy to make the most incredible sounds.
However, you need to know that when you go beyond this $2,000 limit and enter into the large classic vintage dual oscillator poly synths (OB-Xa, old prophets, Jupiter 8) you get a synthesizer that you will want to use all over your music. It speaks to your heart like a drum set, acoustic piano, or guitar. If I was forced to choose between my Prophet 12 and OB-Xa, it would be a painful choice. I would lose the power and versatility of the Prophet 12 yet the pure love of the OB-Xa. My brain would take the P12, but my heart would take the OB-Xa, and usually in life, the heart wins over the mind...
There are several physical reasons why the OB-Xa sounds so good, but one that few (if any) can match is the sensational sound of the filters and resonance. Plus, the OB-Xa is a pure joy to program even though it doesn't have the features found on the Prophet 12.