How much does it cost to have my chin made smaller and possibly rounder such as in the picture below? (Photos)

It is a tempting and easy fix just merely shave the chin edges with a
burr, very accessible technically and very little training is needed.
However under no circustances I do support or recommend (neither practice,
obviously) the chin "shaving" with a burr, which is what you seem to
have interest in. Chin burring is easy, needs little or no planning, can be
done with a submental incision and requires very little skills or
calculations, however has major and unacceptable downsides:
-flattens
and deletes the natural chin prominence, its dome, and commonly makes
the labiomental fold disappear or close to be deleted
-forces to
total dettachment of mentalis rhape, otherwise full countur to burr the
chin is unfeasible, leading to a flaccid, droopy, hollow and unestable
chin, which commonly ends in droopy chin, double chin or jowls and
double chin increase or formation, requiring reoperation
-makes impossible versatile manuvers like horizontal width reduction and other multidimensional modifications
I understand you want a reduction in your chin, which is a very
common request in the office among osseus genioplasty patients, like is my
case and experience after decades performing this procedure. Viewing
your images your diagnosis is of an oversized chin with this
disaggregated technical assessment:
-very slight anterior excess / prominence
-moderate vertical excess
-significant horizontal width excess and too masculine square shape
Should you be my patient I'd have you know the former conditions and suggested
a multidimensional osseous reduction genioplasty, consisting in a
series of precision cuts on the chin bone based on a meticulous preop
radiologic planning as per your cephalometry. The plan would be:
-oblique
up-down + rear-forwad osteotomy with the preop planned angle on the
prominent chin with a subsequent resection of a same-angle slice of bone
as per preop calculations; this would provide both anterior
deprojection/reduction and vertical shortening in the agreed amount
-the
horizontal width excess and the square look is addressed cutting a chip
of cubic bone in the very right center of the split chin portion, as
per preop planning
-final assemble is made with steel wiring so
that stabilization and mounting the puzzle is achieved, creating a three
dimensional reducion genioplasty effect (many cases personally done
like this) in the preoperatively agreed and planned grade, still
preserving the round shape and the nicely shaped chin prominence, making
a good facial balance, without chin droopiness, without double chin or
jowls formatio/increase, thanks to NOT DETTACHING the mentalis muscles
and the soft chin apart from the osseous chin, this is a FUNDAMENTAL
care that HAS TO be taken whenever you perform genioplasties, keeping
the tendinuous rhaphe of the mentalis muscles attached to the severed
and split chin bone fragment, not doing so creates chin flaccidity, chin
droopiness, double chin and formation/increase of double chin and
jowls.If you wish better grounded opinion well lit, focused and standard images have to be assessed: frontal, both lateral and both oblique views.
Feel free to request any additional information from me.

Cost factors vary significantly for a number of good reasons: Prices vary greatly because the surgery itself encompasses a wide range of techniques that can be performed to different extents. My recommendation is to first find the most qualified surgeons where you want the surgery performed that are board certified by the American Board of Plastic Surgery you trust, then compare prices between them. See the below link on suggestions on how to find the most qualified plastic surgeon for your procedure. General Factors that influence the price of plastic surgery include:


1. Location - Will it be performed in a hospital with an overnight stay, an independent out- patient facility or a doctor’s office? Geographical location also has a significant influence. RealSelf has average charges for most areas of the USA.


2. Type of Anesthesia - local, IV sedation or General Anesthesia? Will a board certified anesthesiologist, nurse anesthetist, or an RN be used?
    
      3. Experience and training of your surgeon. The best and longest trained is most often a plastic surgeon board certified by the American Board of Plastic Surgery
   
      4. Length and Complexity of Surgery - how difficult will your surgery be and how long it will take, etc. Will other complementary procedures also be also performed during the same surgery?

You would need to have a submental chin reshaping procedure done to reduce the bone and the soft tissue. Such a procedure would cost in the $5500 to $6500 range for all surgical costs.