To me a complex vco is an absolute must.
My favorite and goto is the DPO. For wavetables I use the Shapeshifter. I also have 1010 music MOK Waverazor which is very effective but a highly specialized dual vco. I also have the Bataleur by Birdkids which has dual vco capabilities.
I was using the Furthrrrr Generator and it really is fantastic, however I decided to let it go and stick to the DPO, it is when all is said and done the character that i like the most and thats ultimately what it comes down to for me, taste.
But for less than 120 euros you can get Doepfer A-110-4 Thru Zero Quad VCO SE.
With that one you can start experimenting with what you already have like the guys are suggesting.
Good luck