I’ve noticed the same 3 models.
About budget - like most I don’t want to spend money needlessly but I also want to know that the Susvara sounds as good as it can. Anywhere from $1,000 to $4,000 for a DAC/AMP combo or stack.
Size - 8 inch 20cm width / 7 inch 17.75cm depth / 4 inch 10cm height would look reasonable on my desk. I can go up to 10 inch 25cm width / 8 inch 20cm depth if necessary but it’ll take up too much space on my desk to look visually proportional.