I started solids with my son at 6.5 months so never used a blender at all.
Started at 6 months with my daughter, who was my first, so I did puree for the first month or so.
If you are starting near 6 months it is likely the blender will only get used for the first month then sit in a cupboard, so if you do want one then go for a basic hand stick blender - we got one £5 from Asda.
If starting at 6 months you dont even need to blend - you can just fork mash if you want - makes it all so much easier. If you steam your carrots then they go soft and can be fork mashed, if you want add a bit of milk